Way before Nirvana
There was U2 and Blondie
And music still on MTV
Her two kids in high school
They tell her that she's uncool
Cause she's still preoccupied
With 19, 19, 1985 (1)
Introduction
I. Back to the Future?
A. The (Unhappy) History of the Exclusionary Rule
B. The "New" Exclusionary Rule Debate: Hudson and
Herring
1. Hudson
2. Herring
II. Normative and Empirical Dimensions of the Overdeterrence
Hypothesis
A. The Overdeterrence Concept
B. Police Incentives
C. Testing the Overdeterrence Hypothesis
1. Warrant Searches
2. Warrantless Searches
3. Terry Stops
4. Police Brutality
5. Arrests
6. Summary of the Evidence on the Overdeterrence
Hypothesis
III. Rights-Based Theories of the Exclusionary Rule
IV. Virtual Deterrence
A. Virtual Deterrence: The Basic Idea
B. Pros and Cons
C. The Bottom Line on Virtual Deterrence
Conclusion

INTRODUCTION

The exclusionary rule for evidence found in violation of the Fourth
Amendment is, again, in play. In Hudson v. Michigan, (2) the Court held
that the exclusionary rule does not apply to violations of the Fourth
Amendment's knock-and-announce requirement. This by itself was not
surprising. Justice Scalia's majority opinion, however, joined by
Chief Justice Roberts, Justice Thomas, Justice Kennedy, and Justice
Alito, contained language, gratuitous to the result, lamenting the
"substantial social costs" of the exclusionary rule,
questioning the need for the "massive remedy" of exclusion,
(3) and claiming the effectiveness of alternative remedies. The phrase
"substantial social costs" appears three times in the majority
opinion. (4) Justice Breyer's stout dissent, joined by Justices
Stevens, Souter, and Ginsburg, replied that exclusion would deter
violations (5) and threw cold water on the claim of effective
alternatives. (6) Justice Kennedy, who joined in the majority, filed a
concurrence including the assertion that "the continued operation
of the exclusionary rule, as settled and defined by our precedents, is
not in doubt." (7) He was the only justice to express this
particular view.

Just this January, in Herring v. United States, (8) the justices
divided into the same blocs. This time, however, Justice Ginsburg's
dissent raised the ante, by arguing that the familiar cost-benefit
approach to applying the exclusionary rule is misguided. (9) For the
first time since Justice Brennan left the Court, members of the Court
appealed to broader justifications for exclusion, including concerns for
judicial integrity, judicial review, and long-run and indirect
influences on official behavior. (10)

The ideas in this "new" debate, however, are about as
fresh as the musty air of an antique shop. The Justices have added
nothing to the stock arguments of their predecessors on the Burger
Court. I find myself wearing the remains of my hair long, putting on
wide ties, reading dismal economic news, and seeing in the latest pages
of the Supreme Court Reporter the United States v. Leon decision (11)
being countered by appeals to 1983 law review articles and prior
dissenting opinions by Justice Brennan. (12) It could be 1985 all over
again.

This Article has two objectives. The first is to discredit both the
majority and dissenting positions in Herring. I contend that the loss of
evidence is a cost of the exclusionary rule, as distinct from the Fourth
Amendment, only in a precise technical sense. It is conceptually
possible that the rule might deter borderline but legal police activity.
(13) While that cost is conceptually possible, the empirical evidence
does not suggest that it is significant. (14)

Notions of a right to exclude illegally-obtained evidence based on
unitary-transaction theories or judicial integrity are equally unsound.
(15) They rest on a conception of substantive Fourth Amendment rights
that goes beyond personal security and informational privacy to include
a constitutional right to private crime. Moreover, right-to-exclude
accounts indeed threaten the good-faith immunity defense in tort, (16)
with the attendant risk of overdeterrence. If Justice Ginsburg invoked
the Brandeis and Brennan views of exclusion because she believes that
the cost-benefit cases have shortchanged deterrence (a correct
apprehension), the Herring dissent is less than candid, as well as less
than logical--a red Herring, as it were.

My second objective is more constructive. I have previously
suggested the suppression of evidence contingent on the failure to pay
damages. (17) If damage actions really were a good remedy for typical
violations, I would stand by this idea. Assessing the damages, however,
is difficult and dangerous. If damages are set too high, they will
overdeter; if set too low, they will underdeter. Using the
administrative machinery of the motion to translate suppression into
damages, therefore, takes an interesting road to the wrong destination.

Whether achieved by suppression or by damages, deterrence operates
by giving the police incentives to prevent future violations. There are
different administrative means to this end. If the violation is
negligent, retraining the officer or instituting more intensive training
programs for the wider force are plausible options. If the violation is
reckless or intentional, discipline as well as retraining may be
appropriate.

If the point of exclusion is deterrence, why exclude now and hope
the police take preventive action later? Why not, in other words,
suppress tainted evidence, then give the prosecution the opportunity to
prove the precise, concrete steps the police department has taken to
prevent recurrence? If the court finds the corrective action adequate,
the evidence could be received; if not, it would be suppressed.

Part I locates the current controversy in historical context, a
prelude to Part II's attack on the Herring majority's concept
of the exclusionary rule's costs and Part III's attack on the
Herring dissent's turn to theories other than deterrence. Part IV
makes the case for my revised contingent exclusionary rule, an approach
I call, in keeping with my plea for modernity, "virtual
deterrence."

I. BACK TO THE FUTURE?

A. The (Unhappy) History of the Exclusionary Rule

The doctrinal history of the exclusionary rule is well known and
can be briefly summarized. Weeks v. United States permitted a pretrial
motion for the return of property in order to prevent the
government's use of incriminating evidence against the search
victim. (18) Weeks made sense given the dual doctrines of Boyd v. United
States: the Fourth Amendment forbids the seizure of evidence other than
contraband, fruits, and instrumentalities, and the Fifth Amendment
forbids the use of the accused's property to prove his guilt at
trial. (19) Silverthorne Lumber Co. v. United States retained the
exclusionary rule despite a corporation's lack of Fifth Amendment
rights, (20) and Agnello v. United States blessed the suppression of
contraband seized in violation of the Fourth. (21)

Some states followed Weeks and some states did not. In Wolf v.
Colorado the Court held that the Fourth Amendment applies to the states
through Fourteenth Amendment due process, but refused to apply the
exclusionary remedy on unwilling states. (22) Twelve years later, Mapp
v. Ohio reversed the latter holding. (23)

The Mapp opinion faithfully reflected the doctrinal incoherence of
the federal exclusionary rule cases, which remained premised on property
rights and the self-incrimination privilege, but often disregarded these
premises to reach results calculated to regulate federal law-enforcement
agencies, as in Agnello. Mapp cited the ineffectiveness of other
remedies, (24) the need to deter misconduct, (25) and "the
imperative of judicial integrity." (26) Only Justice Black, who
supplied the fifth vote, worked from the Boyd doctrine to reach the Mapp
result. (27) Since Twining v. New Jersey (28) and Adamson v. California,
(29)--holding that the Fifth Amendment self-incrimination privilege did
not apply to the states through the Fourteenth Amendment--were not yet
overruled by Malloy v. Hogan, (30) this is perhaps not surprising.

Subsequent cases made clear the salience of the deterrence
rationale. Linkletter v. Walker (31) refused to apply Mapp
retroactively, a result consistent with the deterrence theory. Alderman
v. United States (32) retained the standing requirement, a seeming
retention of the Fifth Amendment theory, but the opinion took pains to
stress that the search victim's right to exclude provided adequate
deterrence of Fourth Amendment violations. (33)

Through Alderman, the history of the exclusionary rule tracks the
history of the Fourth Amendment generally. The early federal Fourth
Amendment cases reflected an "atomistic" conception of the
Amendment as protecting individual entitlements to property, privacy,
and personal security. (34) Searches were defined as tortious trespasses
upon private property interests; (35) executive-branch agents could not
engage in such trespassory activity without a judicial warrant; (36)
warrants by their terms could be issued only with probable cause and the
agents logically could have no greater power without judicial
authorization than with it. Even when authorized by a valid warrant, the
seizure of any property other than fruits, instrumentalities, or
contraband was held to violate the Fourth Amendment. (37) Exclusion,
exemplified by Weeks, aimed to restore the status quo ante when the
government's agents had broken into private spheres without lawful
authority.

The logic of this atomistic perspective, however, often yielded to
the "regulatory perspective," the perceived necessity to
discourage lawless actions by the police, even when those actions could
not be equated with tortious invasions of private property rights.
During the Prohibition Era, contraband booze could be the subject of
suppression and even of return. (38) This surely reflected some degree
of sentiment for nullification, but it also reflected a quite principled
concern that if contraband could not be suppressed there would be no
effective deterrent to unconstitutional searches.

The Warren Court moved further along the regulatory path by
classifying electronic eavesdropping without trespass to the suspect as
a "search," (39) and by rejecting the mere-evidence rule that
had been the premise for search and seizure law since Entick v.
Carrington. (40) In Terry v. Ohio, the Court treated coercive
stop-and-frisk practices--tortious prima facie--as seizures and searches
that could be justified by less than probable cause, thus within the
power of the police, even though the text of the Constitution gives
judges no explicit power to authorize them. (41)

Linkletter set the stage for a full and candid turn to a regulatory
approach, rooted in deterrence, to the exclusionary rule. Doctrinal
development, however, coincided with political change. Reflecting the
electoral sentiment of the 1970s, new justices showed more concern for
law enforcement. United States v. Calandra embraced a purely deterrent
view of the exclusionary rule, expressive of a new Supreme Court
majority more sympathetic to law enforcement than the last. (42)
Suppression is costly and must be justified by deterrent benefits, and
an exception should be created whenever those benefits are not clear.
Subsequent cases took this approach repeatedly. In only one case--James
v. Illinois (43)--did the Supreme Court's balancing test incline in
favor of the defense. In more than half a dozen others (United States v.
Janis, (44) Stone v. Powell, (45) United States v. Havens, (46) United
States v. Leon, (47) Massachusetts v. Sheppard, (48) Illinois v. Krull,
(49) and Arizona v. Evans (50)), the Court approved government use of
tainted evidence.

The majority opinions in these cases stubbornly refused to answer
two powerful opposing arguments. The first is that the Fourth Amendment
prohibits some searches that would discover evidence of serious crimes,
so that the loss of evidence attends any effective deterrent of Fourth
Amendment violations. The description of lost evidence as a
"cost" was therefore hostile not to the exclusionary remedy,
but to the underlying Fourth Amendment right, one the justices in the
majority did not deride and which, in any event, they were sworn to
uphold.

The second argument is that the Court's opinions gave no
criteria for determining when deterrence was expected to be adequate and
when it was not. When confronted with case-specific reasons to predict
positive incentives for constitutional violations, the stock rejoinder
was that these concerns were "speculative." (51)

The current state of exclusionary-rule jurisprudence can be
summarized as the very odd product of progressive doctrine applied by
reactionary justices. The turn to regulatory Fourth Amendment theory was
called for by institutional and technological changes quite aside from
ideological changes on the Court. Professional police, organized crime,
and electronic surveillance made the ancien regime untenable. The
reworking of Fourth Amendment law away from the atomistic perspective
was inevitable and no Justice, even one with strong originalist
pretensions, seems inclined to rethink it. (52)

B. The "New" Exclusionary Rule Debate: Hudson and Herring

1. Hudson

The issue in Hudson v. Michigan was whether the exclusionary rule
applies to evidence obtained in the search of a residence authorized by
a valid warrant, but executed inconsistently with the knock-and-announce
requirement announced in Wilson v. Arkansas. (53) The Court divided
five-to-four, holding that the rule does not apply. This result could
have been reached on the ground of inevitable discovery. (54) The
majority noted as much. (55)

Part III.B of the opinion nonetheless deployed the now familiar
cost-benefit balancing test. (56) The majority went so far as to say
that the costs of exclusion outweighed the benefits even if the
knock-and-announce rule would be nullified by withholding this remedy.
(57) Justice Scalia's discussion repeats the pro-police mantra:
exclusion is a "massive remedy" (58) that carries
"substantial social costs." (59)

The opinion adds, however, another argument: Fourth Amendment
remedies may have been inadequate when Mapp was decided in 1961, but
those remedies are much stronger now. (60) Justice Scalia pointed to the
recognition of entity liability in Monell v. New York City Department of
Social Services, (61) the provision authorizing payment of
attorney's fees to successful [section] 1983 plaintiffs, (62) and
the increasing professionalization of the police. (63)

Like his predecessors on the Burger Court, Justice Scalia did not
mention two cogent and long-standing arguments against the cost-benefit
analysis. One is that the cost of lost convictions is attributable not
to the exclusionary remedy, but to the underlying Fourth Amendment
right. (64) If the police complied with constitutional standards, the
evidence would never be discovered and the guilty would remain at large.

In unusual cases, like the knock-and-announce cases, compliance
with constitutional standards does not prevent the discovery of the
evidence. The inevitable discovery exception covers these cases.
Whenever Fourth Amendment doctrine forbids evidence, there is a
"cost" only if a current policy preference for unlimited
law-enforcement is given priority over the constitutional preference for
limiting law enforcement power.

In a minority of cases, exclusion costs the public a conviction the
police might have achieved later without violating the Fourth Amendment.
When police have probable cause but don't bother getting a warrant,
or when they search an automobile with less than probable cause but
later learn of information that would have gotten them over that hurdle,
we can say that the exclusionary rule, rather than the Fourth Amendment,
caused the loss of the evidence. Most of the time, however, the police
never could have made a case without violating the Fourth Amendment; the
inevitable discovery exception again covers many of the cases where they
might have done so. (65)

The second familiar argument Justice Scalia ignored is related to
the first. Any effective remedy for Fourth Amendment violations will
carry those same "substantial social costs." (66) Justice
Scalia seems to be in a celebratory mood in writing about damage actions
and police professionalism, as if searches that don't take place
because of the threat of tort liability or departmental discipline are
somehow different from searches that don't take place because of
the threat of exclusion.

These points have been in the literature since the 1920s. (67) If
they were bad arguments we would expect exclusionary rule critics to
acknowledge them and reply. Anyone who was a fair-minded critic of the
exclusionary rule who had such a rejoinder would surely have deployed
it.

The claim that modern tort suits and modern police departments have
made the exclusionary rule unnecessary reflects the same prejudice
against the exclusionary rule. Legal recognition of municipal liability
is both difficult to establish (68) and practically irrelevant. Cities
and police departments typically pay for the defense of claims against
individual officers and indemnify the officers after a settlement or a
plaintiff's verdict. (69) In 1976, Congress passed 42 U.S.C.
[section] 1988(b), authorizing attorney's fees for successful
plaintiffs. There is no correlative provision for Bivens actions. (70)

The practically relevant rules for damage actions against the
police thus have not changed for more than thirty years. If there has
been a change, it has been cultural rather than legal. Marc Miller and
Ron Wright's survey of reported settlements of suits against police
presents persuasive evidence that the police can be sued successfully.
(71) Previous empirical work, however, indicated that recoveries against
the police would be substantial primarily when the police had inflicted
physical injuries, especially when the police acted in bad faith. (72)
As Wright and Miller point out, the secrecy of settlements means that we
can only speculate about the nature of the claims. My own suspicion is
that most of the settlements reported by Wright and Miller involved
claims based on Tennessee v. Garner (73) or Graham v. Connor, (74) not
illegal stops, arrests, or auto searches.

The inability of the Hudson majority to find a single successful
tort suit for violation of the knock-and-announce rule is illustrative.

2. Herring

The Court characterized the issue in Herring v. United States as
whether evidence found in a search incident to an arrest, based on an
erroneous police record of an outstanding arrest warrant, should be
suppressed. (75) The same Justices that composed the Hudson majority
held that the evidence should be admitted. Speaking this time through
the Chief Justice, the Court deployed the Calandra cost-benefit
analysis, and concluded that:

To trigger the exclusionary rule, police conduct must be
sufficiently deliberate that exclusion can meaningfully deter it,
and sufficiently culpable that such deterrence is worth the price
paid by the justice system. As laid out in our cases, the
exclusionary rule serves to deter deliberate, reckless, or grossly
negligent conduct, or in some circumstances recurring or systemic
negligence. The error in this case does not rise to that level.
(76)

In a footnote to this passage, the majority engaged the dissenters
as follows:

We do not quarrel with Justice Ginsburg's claim that "liability for
negligence ... creates an incentive to act with greater care," and
we do not suggest that the exclusion of this evidence could have no
deterrent effect. But our cases require any deterrence to "be
weighed against the 'substantial social costs exacted by the
exclusionary rule,'" and here exclusion is not worth the cost. (77)

In this revealing passage, the majority agrees that suppression
would prevent future violations of the Constitution, but characterizes
prevention of constitutional violations as not worth the loss of a
single case against a hoodlum so dysfunctional that he cannot drive to
the impound lot without his contraband.

Two dissenting opinions quite cogently challenged the
majority's general deterrence analysis (78) and the extension of
the Leon-Evans line of cases to records maintained by the police. (79)
These points, however, accept the basic Calandra framework. All four of
the dissenters, Justices Ginsburg, Stevens, Breyer, and Souter, also
endorsed a direct attack on that approach.

Echoing earlier dissenting opinions by Justice Brennan and Justice
Stevens, and the views of Professor Yale Kamisar, Justice Ginsburg
argued that exclusion serves purposes other than deterrence and is an
integral component of the substantive constitutional right. (80) That
view is examined more closely (and critically) in Part III. For present
purposes it suffices to say that the exclusionary rule is back, but
unchanged since the 1980s. A bloc of five Justices regards compliance
with the Fourth Amendment as a cost and exclusion as accordingly
disfavored, while a bloc of four dissenters would sever the exclusionary
remedy from deterrence calculations and tether it instead to the
underlying substantive right.

In my view, both blocs are wrong. The next two parts of this
Article explain why. (81)

II. NORMATIVE AND EMPIRICAL DIMENSIONS OF THE OVERDETERRENCE
HYPOTHESIS

A. The Overdeterrence Concept

Remedies for the violation of legal rules optimally deter when
potential violators rationally expect the violation to have a value of
zero. (82) If violations can be expected to return net gains, the rule
will be violated even when compliance would be possible at lower net
cost. If the regulated actors rationally anticipate the value of
violations to be negative, they will refrain from borderline but legal
conduct with positive benefits, or adopt precautions that cost more than
the value of the violations they prevent.

The standard tort model has some plausibility as applied to suits
against the police. Given the prevalence of defend-and-indemnify
arrangements, cities or police departments are repeat players estimating
the benefits and costs of their agents' behavior with respect to a
large pool of cases. In many of the cases in the pool, the legality of
police action will be uncertain ex ante. So overdeterrence and
underdeterrence are both possible. The police could avoid all Fourth
Amendment violations by playing pinochle in the station house, and they
could uncover a lot of evidence by searching on mere suspicion or en
masse. Society favors neither extreme, and this looks a lot like how we
think about industries that cause some harm but confer great benefits,
like mining, transportation, power generation, and so on.

The difficulty in applying the optimal-deterrence prescription to
search-and-seizure is that there is no symmetry between the gains the
regulated actors secure from violations and the cost of those
violations. Such symmetry is thought to exist in tort law, where damages
are set so that the tortfeasor's damages equal the value of the
plaintiff's loss, with punitive or pain-and-suffering damages
thrown in to account, very roughly, for the reality that the probability
of a successful suit, even in meritorious cases, is less than one.

When the police kill or injure the victim, tort damages can be
estimated just as the tort system estimates damages for wrongful death
or personal injury in other cases. Even here, however, there is good
reason to doubt that damage actions achieve optimal deterrence of
unlawful police violence. The qualified-immunity defense means that
police violence incurs liability only when clearly excessive. The police
employer therefore does not expect to internalize the costs of every
illegal police shooting or beating, with corresponding incentives to
train and discipline the force. There are political incentives at work
as well, but those may work in favor of aggressive policing as well as
against it. Police immunity gives reason to doubt whether we are
optimally deterring even police violence.

Damage actions, however, offer the only practical remedy for police
misconduct not motivated by the desire to initiate a formal prosecution.
The exclusionary rule does not deter police who beat up citizens for
sport. If we abolish qualified immunity (which was as unknown to the
founders as the exclusionary rule (83)), we might come closer to optimal
deterrence. The risk, however, is that the prospect of liability might
induce the police to refrain from violence even when justified, leading
to the escape of dangerous felons. The immunity defense was created to
prevent this very contingency. (84)

The exclusionary rule influences police behavior in the pool of
cases in which the objective of the search or seizure includes enabling
a formal prosecution. Strictly speaking, the victim of an unlawful
search who is prosecuted may both suppress the evidence on the criminal
side and sue the officers on the civil side. Indeed, the Supreme Court
has upheld so called plea-bargain/release agreements, in which the
search victim waives civil remedies as part of a plea deal. (85)

Typically, however, exclusion operates in cases where damage
actions face formidable valuation problems. We can perhaps estimate the
employer's benefit from the government's willingness to pay
tens of thousands per year to incarcerate the guilty and the added
expense of the police force itself. Any such calculation will typically
dwarf the economic damage from unlawful stops, searches, and even
arrests. Guessing about liquidated damages runs the risk of
overdeterrence.

The Hudson majority supposes that this remedial mix of damage
actions, limited by qualified immunity, and the exclusionary rule, is
overdeterring Fourth Amendment violations. To unpack the overdeterence
hypothesis, we should begin with a normative point. Knowing violations
of the Constitution cannot be justified by police calculations of costs
and benefits. Suppose police have probable cause to believe that a
murder weapon can be found in a particular house, but they have no
warrant to search. Suppose, further, that they know the house to be
temporarily unoccupied. Entry, therefore, would disturb no one. Now
suppose that the residents have left a window open, so that the police
could enter without doing any damage to property. The police have no
warrant, but they are confident one would be issued if they applied for
one. They are also confident that their department would cheerfully pay
whatever a tort suit might cost to make a major case. Exclusion gives
them an incentive not to enter and search the house; is this
overdeterrence?

The Supremacy Clause says no. Presumably the
compelling-state-interest safety valve applies in Fourth Amendment
cases, so that if catastrophic consequences would follow from compliance
with the usual constitutional rules, the police might disregard those
rules without violating the Constitution. This is analogous to Congress
enacting a law authorizing censorship of the news in wartime, the text
of the First Amendment notwithstanding. If, however, we leave the
compelling-interest scenario aside, the police should do exactly what
the exclusionary rule encourages them to do--get a warrant, even if this
means that the evidence may disappear before it can be seized.

The same normative analysis applies to searches permitted by the
Constitution without warrants, but only on condition of probable cause
or reasonable suspicion. Suppose a thousand cars are parked by a valet
service for a Rolling Stones concert. The police could, at negligible
cost, seize the keys from the service and search every vehicle. Does the
Fourth Amendment permit them to balance the costs of search against the
value of evidence, or does it rather balance those values independently
of current policy preferences by requiring probable cause?

The position I am defending is different from the claim that the
Fourth Amendment establishes a property rule rather than a liability
rule. (86) I have tried over the years to conceptualize the Fourth
Amendment as a liability rule or a property rule, but the private-law
dichotomy does not easily transpose to a constitutional limit on the
public force. Indeed, because the property/liability distinction turns
on remedies rather than rights, the variety and controversy over
Fourth-Amendment remedies renders the private-law distinction
problematic in this context. Rather, the Fourth Amendment protects
particular individual interests against government encroachment absent
specified prerequisites. This substantive rule is protected by a mix of
remedies. Egregious violations are punishable both criminally (87) and
by punitive damages. (88) Ongoing violations can be enjoined, (89) even
when undertaken in good faith based on legal advice. (90)

Professor Kontorovich makes a useful point by distinguishing
slow-moving from fast-moving Fourth Amendment events. (91) Obviously
enough, in most cases, Fourth Amendment violations can be remedied only
ex post, typically by exclusion, damage actions, or both. To say that ex
post remedies are the only ones we have is not to say that the sanction
for violations should equal either the victim's loss or the
violator's gain, because in the Fourth Amendment context these are
different.

There may be violations for which damages provide the best
practical remedy, but those damages are not, and should not, be limited
by compensation; rather, they should be set high enough to eliminate all
but irrational incentives for violation. Private law abhors holdouts and
eccentrics. The Fourth Amendment protects them. The government has no
more right than, say, Bill Gates to break into houses or lock people up
with a cheerful willingness to pay damages ex post.

What makes some knowing violations of the Fourth Amendment look
attractive is the failure of substantive doctrine to factor the
seriousness of the suspected offense into the determination of
reasonableness. Professor Stuntz has criticized the transsubstantive
character of Fourth Amendment jurisprudence. (92) Prevailing doctrine
might be justified by the tendency of judges to consider offense
severity in practice. However one resolves the transsubstantive issue,
the issue is one of substantive, rather than remedial, law.

In the Fourth Amendment context, then, overdeterrence does not mean
that the monetized expected value of evidence that might be found from
illegal searches exceeds the expected damages to be paid for those
searches. (93) The substantive constitutional provision has balanced the
costs and benefits of those searches quite differently. Overdeterrence
of constitutional violations, therefore, means discouraging lawful
police actions in a pool of cases where the legality of prospective
actions is uncertain.

The Hudson majority is therefore wrong to characterize the loss of
reliable evidence as the "substantial social costs" of the
exclusionary rule. Justice Roberts's smug reference to the
prominence of prior dissents in Justice Ginsburg's Herring opinion
(94) would make a better point if prior majority opinions spoke to the
argument that they were treating violations of the Constitution as
desirable and compliance with the Constitution as a cost. As those
opinions stand, the Chief Justice appears to take comfort in the
frequency with which this error has been repeated.

However we enforce them, limits on police power facilitate crime.
There should be no blinking of the fact that freedom and safety do
conflict. A free society will have more crime than a police state, and
crime is undoubtedly a "substantial social cost." That cost,
however, is properly charged to freedom itself. (95) Were it not for the
Fourth Amendment, plenary search powers might very well prevent some of
the very worst crimes--terrorist attacks like those of 9/11 or the
repeated incidents of rape, torture, and murder perpetrated behind
closed doors by the likes of John Wayne Gacy or Leonard T. Lake. Were it
not for the Fourth Amendment, plenary search powers certainly would make
the production and distribution of cocaine, heroin, and child
pornography on an industrial scale much more difficult. We retain,
indeed revere, the Fourth Amendment in spite of these horrific
consequences.

The Fourth Amendment is one of those civil liberties the United
States has fought its wars to establish and preserve. General warrants
and the writs of assistance were among the grievances inspiring
revolution.96 Sweeping search and arrest powers were a necessary
component of the odious southern slave apparatus. (97) The Second World
War and the Cold War (including the shooting wars in Korea and Vietnam)
were waged with the object of preventing the global hegemony of
aggressive police states. (98) In the latter struggle, the United States
stood ready to use nuclear weapons against cities. (99) In the former
struggle, it actually did so. (l00)

If the Fourth Amendment is worth waging war, it is worth tolerating
crime. We can be grateful that sophisticated policing and pragmatic
doctrine keep that cost as low as it is. (101) We should not, however,
sugarcoat the facts. The choice between freedom and security is tragic,
in the sense that however a political community makes that choice, some
innocent people will suffer terribly as a result. In our political
community we have made that choice, as irrevocably as we can, against an
unlimited commitment to security. Loose references to lost evidence as a
"cost," made without reference to the constitutional judgment
that the better course is not to gather all possible evidence of crime,
should be banished from the law and from the literature as the veiled
attacks on the Constitution that they are.

If we take the substantive Fourth Amendment law as given and worthy
of content-independent respect, it follows that the police should be
trained to refrain from searches and seizures whenever the proposed
action is more likely than not illegal. The reverse is not true; the
police may often gain an advantage by delaying a stop, search, or arrest
for some time after they have established legal grounds. The current
remedial mix would overdeter if, and only if, the police have a net
incentive to refrain from searches and seizures for other than tactical
reasons, even when the potential action is probably legal.

B. Police Incentives

Police behavior on the street is the product of a long sequence of
agency relationships. Voters elect a municipal government, the
government establishes a police force, and the administrators in charge
of the force train its officers and reinforce this training by rewarding
compliance and punishing noncompliance. A brief look at the relationship
between officers on the street, whose conduct is the actus reus of any
Fourth Amendment violation, suggests that the focus of policy analysis
should be on police administrators. Individual officers do not
internalize either the benefits or the costs of Fourth Amendment
activity. When the police apprehend an offender, they may improve their
performance evaluations and gain prestige within the force. They do not,
however, pocket what the community is willing to pay to prosecute and
punish the offender.

Nor do individual officers internalize the costs of Fourth
Amendment activity. The police get paid whether or not they are deployed
to their highest use. If police seize evidence in violation of the
Fourth Amendment, the evidence may be suppressed, but the police are not
automatically fined or jailed. Although the practice is somewhat
subterranean, cities and departments apparently pay for the defense of
lawsuits against individual officers, and, when the individuals are
liable, indemnify the individual officers for the cost of damages or
settlements. (102) Individuals, therefore, do not internalize (nor do
they expect to internalize) these costs. (103)

So the law influences street-level behavior primarily by giving
police administrators incentives to train and discipline the force to
comply with constitutional requirements. Call whomever is in charge of
the police, the employer, R. Let us assume that R is a rational actor
with an incentive to maximize measurable indicia of crime control
(arrests, clearance rates, convictions, reductions in reported crimes,
maybe even victimization survey numbers). Let us further assume that R
is obligated, by contract or custom, to defend and indemnify employees
against civil rights actions.

Built into this model is an important and nonobvious assumption.
The model assumes that R has no content-independent respect for law. If
R has a taste for complying with formal legal prescriptions, R will
train and discipline the force to be more compliant than the model
predicts. The assumption is debatable but in my view justified by the
available information. (104)

R will train and discipline the force NOT to act unless:

EB [greater than or equal to] EC

where EB is R's expected benefit from action and EC is
R's expected cost. EB, the expected benefit, can be broken down
into nonevidentiary benefits ("NEB") and evidentiary benefits
("EVB"). NEB includes such gains as discouraging crime by
visible patrol presence or preventing domestic violence by arresting the
abusive boyfriend. EVB includes the gain from enabling prosecutions
based on evidence expected from a prospective action.

EC can be broken down into opportunity cost ("OC") and
liability cost ("LC"). Once the funds are appropriated to pay
for the force, the cost of those funds is fixed. The force itself,
however, can be deployed in different ways. Police engaged in routine
patrol could be working undercover drug operations or gang
investigations. The size of OC depends on the expected benefits from the
next-best-use ("NBU") that might be made with the quantity of
resources ("QR") devoted to any given operation.

R has an incentive to deploy the force to its highest uses measured
by whatever crime-control measures R adopts. The next-best use for
marginal police resources is the value of R's highest unmet
priority--which is small enough that given R's budget constraint,
that priority is not addressed at all. The size of OC therefore depends
to some extent on whether the police face a target-rich or target-poor
environment. OC will be greatest when a police operation consumes large
resources in a target-rich environment, and smallest when the operation
consumes modest resources in a target-poor environment.

The primary effect of the exclusionary rule is to reduce EVB. If
the police are certain that a proposed search will be held legal, EVB is
unchanged. If the police are certain that it will be held illegal, EVB
is reduced to zero. In uncertain cases, if evidence is found, there will
be a probability of exclusion; call it PX. The effect of the
exclusionary rule is to multiply EVB by (1-PX).

The risk of exclusion also changes the opportunity cost term,
because one cost of a search is the risk that the evidence will be
discovered at a time when the police lack probable cause or reasonable
suspicion but could have established it later had they delayed and
sought additional supporting information. This cost--the normatively
relevant cost of exclusion--is reduced, but not eliminated, by the
inevitable discovery exception. The inevitable discovery exception
requires proof by a preponderance that the tainted evidence would have
been found later and lawfully but for the premature police intervention.
(105) In some cases the evidence would have been found later and
lawfully but the prosecution will not be able to prove this. This cost
is genuine, but given the inevitable discovery exception, and the
readiness of judges to make the required finding, I will treat it as
negligible. (106)

So viewed, the exclusionary rule is less a penalty for police
illegality than a bounty for legality. This bounty can influence police
behavior because the opportunity costs and liability risks of action may
outweigh the nonevidentiary benefits but not the total benefits of
action. The exclusionary rule reduces the expected evidentiary benefit,
in direct proportion to the probable unlawfulness of the prospective
search or seizure.

LC has two components, the probability of damages ("PD")
and the quantity of damages expected ("QD"). We can now
describe the incentives facing R by the equation:

NEB + (EVB * (1-PX) [greater than or equal to] (QR * NBU) + (PD *
QD)

The police should act only when they expect the gains, discounted
by the risk of exclusion, to outweigh the opportunity cost plus the risk
of damages.

The present remedial mix would be overdeterring if PX, PD, and QD
are high enough to eliminate the expected net benefit from searches that
are probably legal and otherwise cost-beneficial according to R's
utility function. If this were true, we would expect the police to
refrain from justifiable but borderline searches, by choosing to
intervene only when the legality of their actions is highly probable. I
think this hypothesis can be tested against empirical evidence on the
success rates of different types of searches.

Fourth Amendment law's primary requirement is of some level of
antecedent suspicion. Searches for evidence can only be justified by
probable cause. Investigative stops can only be justified by reasonable
suspicion. If we could agree on numbers for probable cause and
reasonable suspicion, and knew the success rates the police were
encountering in a large sample of cases, we would have some evidence
bearing on the overdeterrence hypothesis. If hit rates were
substantially higher than the prescribed level of antecedent
probability, police would be refraining from high-probability searches.

It might be the case that hit rates are so high that the likely
explanation would be that police action was limited not by the legal
rules but by resource constraints. That seems implausible. Clearance
rates for the index crimes are in the vicinity of 20%. (107)0 That
suggests a target-rich environment (a high rate of offenses relative to
police resources), but also that the targets are not easy to hit. Police
searching at random would not discover a great deal of evidence. If hit
rates are high, it is because OC and LC are high relative to NEB and
(EVB * 1 - PX).

C. Testing the Overdeterrenee Hypothesis

Has the current remedial mix had a chilling effect on police
actions that are probably legal? This seems improbable, both from the
incentives created by the current mix and from what direct evidence we
have of police behavior. When police action is of debatable legality,
the immunity defense insulates the officer from liability, and thereby
the employer from indemnification. Exclusion reduces but does not
eliminate the value of borderline actions, as police administrators
probably derive considerable utility from seizing drugs and weapons even
if these may not be used in court.

The exceptions to exclusion of tainted evidence are one reason.
(108) The standing rule in particular means that the police can
rationally anticipate some legal benefit from illegal searches when
group criminality is suspected. When the police illegally seize
contraband, the drugs or guns are off the streets even if they cannot be
used as evidence. Many, probably most, arrests are made with no
expectation of discovering evidence in the incidental search.

If the adjudication of suppression motions frequently resulted in
false positives--erroneous findings that the police had acted
illegally--exclusion might discourage borderline but lawful actions. If
errors are distributed randomly, however, police administrators would
expect false positives to be balanced by false negatives. In all
probability, false negatives are more likely than false positives.
Sympathetic judges and police perjury reduce the probability that
evidence illegally seized in fact will be so ruled in court.

This assessment of the legal incentives facing police
decision-makers is consistent with the most plausible empirical test of
over or underdeterrence. The literature contains a considerable number
of studies measuring the success rates of different types of searches
and seizures. We can compare the "hit rate" with the level of
antecedent suspicion the law requires for each species of search and
seizure.

If the hit rate is clearly above the legally-required zone of ex
ante probability, in a large sample we could infer either very high
opportunity costs (a police force so small relative to offenses that it
can process only high-probability cases, quite aside from remedies for
legal violations), or overdeterrence (the police have the capability to
engage in high-probability searches but refrain because of the fear of
exclusion and damages). If, by contrast, the hit rate is clearly below
the legally-required zone of ex ante probability, we could infer either
very low opportunity costs (the police have so many resources relative
to offenses that only low-probability cases are left to pursue), or
underdeterrence (the police engage in lots of low-probability, and thus
unlawful, searches, because the benefits of even low-probability cases
exceed the costs).

Prior exclusionary rule research, and more recent research on
racial profiling, has given us some evidence of the hit rates for search
warrants for private premises, warrantless vehicle searches during
traffic stops based on probable cause under United States v. Ross (109)
and California v. Acevedo, (110) and Terry stops (111) of citizens on
the streets. The evidence is not as extensive as one might wish, but it
is evidence, as distinct from mere conjecture of the sort set forth by
the Hudson majority. Let us look at what we know about warrant searches,
warrantless automobile searches, and Terry stops.

1. Warrant Searches

The Fourth Amendment requires probable cause to issue search
warrants. The Supreme Court has resisted quantifying probable cause,
(112) but the governing idea in the cases is that probable cause is
present when the expected probability of success exceeds 50%, while a
lower probability may sometimes suffice. The Supreme Court has read the
Amendment to require warrants for some searches, primarily entry of
homes without consent.

The warrant requirement increases OC because, aside from the
collection of the information showing probable cause, the preparation of
the application and the process of presenting the application to a judge
consume significant amounts of police time. (113) Search warrants have
little NEB; police applying for a warrant are motivated by the desire to
obtain admissible evidence. We should therefore expect that the police
will seek warrants only when EVB is high--above the rough-and-ready 50%
hit rate that would satisfy the probable cause standard.

In 1972, Michael Rebell studied search warrants executed in a
Connecticut jurisdiction in two different years and found that 64% and
70% of the warrants resulted in the seizure of some of the target
evidence. (114) A study for the National Center for State Courts
examined warrant practice in seven cities and found that the success
rate for warrant searches, based on returns filed listing some of the
target evidence seized, in six of the seven cities studied, ranged from
74 to 89%. (115) More recently, Laurence Benner and Charles
Samarkos's study of search warrants issued by state courts in San
Diego found that 65% of the executed warrants authorizing searches for
illegal drugs resulted in the seizures of the target evidence. (116)

Warrant searches succeed at a rate that matches or exceeds the hit
rate prescribed by the applicable legal standard. Does this suggest
overdeterrence? Probably not. The numbers for success have not changed
dramatically since Leon, even if the quality of the applications may
have suffered. Since Leon and Malley v. Briggs, (117) a defective
warrant, absent gross ignorance or deliberate perjury on the part of the
police, will trigger neither exclusion nor damages. The likely
explanation for the high rate of success for searches pursuant to
warrants is opportunity cost. Quite aside from the remedial mix of
damages and exclusion, which have been withdrawn from warrant searches
absent the most egregious facts, police who seek and execute warrants
are interested in evidence and generally have probable cause.

If we view the warrant requirement solely as a means to the end of
ascertaining probable cause in the most rational way, hit rates over 50%
would indeed suggest overdeterrence. There is, however, no exception to
either the substantive right, or the exclusionary remedy, when police
act without a warrant even though probable cause is clearly present. It
would seem to follow that the warrant process has additional purposes,
including that of putting a costly hurdle between the police and the
most sensitive Fourth Amendment interests--the privacy of the home and
of confidential communications. (118)

The remedial mix enters the warrant context by framing the
opportunity cost issue. Why would the police bother with the costly
warrant process? Because the remedial mix makes bypassing warrants too
costly. Search warrants are usually sought for home invasions
(electronic surveillance is another common object). Absent consent or
exigency, which the courts have been pretty scrupulous about with
respect to home searches, the police know that home invasion requires a
warrant. Judges facing a motion to suppress for a warrantless home
search are willing to suppress and may feel no real choice about the
matter. Citizens whose homes have been invaded may well bring suit, and
police who enter homes without warrants are not likely to win on the
immunity defense.

So it is not implausible, but all things considered probably
incorrect, to say that the success rate for warrant searches should be
near the 50% number the probable cause standard might suggest. To the
extent that the Fourth Amendment requires the police to get warrants
based on probable cause, the constitutionally-prescribed hit rate is
higher than what we would expect if the Fourth Amendment required only
probable cause. The warrant requirement adds the cost of the warrant
process to the requirement for home invasions, not just as a matter of
police tactics but as a matter of the Fourth Amendment's
constitutional trump over ordinary policy considerations. Given the
legal requirement of both probable cause and a (costly) warrant, we
should expect the hit rates from warrant searches to be somewhat above
the 50% threshold--which is where it turns out that they are. Only if
the costs to police of obtaining warrants were reduced to zero would we
expect the hit rate to be 50%.

If hit rates for warrant searches are thought too high, the
curtailment of both exclusionary and damage remedies for searches
authorized by warrants suggests that the "culprit" is the cost
of the warrant process. Action to reduce that cost to the police might
move the hit rate closer to the 50% rate we might expect from a perfect
assessment of probable cause ex ante.

Abolition of the exclusionary rule means that the police would
enjoy the full evidentiary benefit of illegal warrantless home
invasions. There are two possible scenarios. If the specter of tort
liability is strong enough, nothing would change. No extra evidence will
be discovered (and so much for the exclusionary rule's social
costs!). If, however, admissibility of the evidence changes the balance
of incentives so that the risk of tort liability is deemed worth the
cost of a search that both the training department and the executing
officers know is illegal, evidence will be obtained but only by treating
the Constitution as unworthy of content-independent respect.

Both scenarios would play out. When the police expect the search
victim to lack the means, the pluck, or the equities predictive of
success in tort to actually sue, warrantless home invasions, a la Mapp,
would flourish. Evidence of crimes by the wealthy, well-educated, and
politically-connected would be just as inaccessible to justice as with
the exclusionary rule.

2. Warrantless Searches

Under Ross and Acevedo, police need probable cause, but no warrant,
to search vehicles for evidence or contraband. Prior to the racial
profiling controversy, warrantless searches were hard to study. Police
executing a warrant are obligated to make a return to the court,
creating a documentary record. (119) No such record typically
accompanies a warrantless search. Now, however, we have some data on
auto searches, developed to address the controversy over racial
profiling. Much of this data concerns the initial decision to stop,
rather than the later decision to search. When hit rates for stops are
reported, the search might be based on consent, or as incident to
arrest, rather than as a free-standing search for evidence based on
probable cause. It is difficult to parse the data to find hit rates for
this particular species of police behavior.

Sam Gross carefully analyzed data collected by the Maryland State
Police. (120) The officers were required to report traffic stops and
subsequent searches, and to identify when the search was based on
consent. Treating all nonconsent searches as based on a claim of
probable cause, Gross found the hit rate for these latter searches to be
just under 48.4%. (121) Again, at least superficially, that is about
where the law says it ought to be.

Gross points out that there are two reasons to think that the
Maryland data overstate the hit rate, perhaps dramatically. First, the
police disliked the reporting requirement, and were, one supposes, far
more likely to report hits than misses. (122) Second, when the data are
parsed for the importance of the evidence seized, the overall hit rate
is far less impressive. If we factor out trace and personal quantities
of marijuana, the hit rate for Maryland probable-cause searches drops to
9.8%. (123)

Of course possessing marijuana for personal use is a crime. It is
not, one supposes, what the police were looking for. A bigger reason to
discount the hit rate, however, follows from the fact that in many cases
probable cause for the vehicle search is derived from discovery in plain
view (or plain smell) of a personal supply of marijuana. In these cases
the search shows up in the overall statistics as a hit, even though the
probable-cause-based search discovered nothing at all.

If the primary mission of the police who make traffic stops is
traffic enforcement, the opportunity cost of the time added to each stop
by a thorough search of the vehicle is high. Traffic violations are
ubiquitous; the state gains revenue from citations and the police have
incentives to issue those citations. In a study of the North Carolina
State Police, William Smith and his colleagues found that troopers on
patrol for speeding or other traffic infractions almost never searched
and, moreover, were loath to do so. (124)

If, however, the primary police mission is drug interdiction, OC is
lower. Undercover investigations to build a record for warrant searches
are time-consuming and dangerous. Sell-and-bust operations are easier
but net only ordinary users. LC for the search, independent of the stop,
is low. Qualified immunity means that liability attaches only to police
who are clearly mistaken about the probable cause issue, and reasonable
people can often disagree about whether probable cause is present or
not. Damages for an illegal roadside search are not likely to be high.

Accordingly, for warrantless searches, the remedy with the most
influence on police behavior is the exclusionary rule. Gross's
numbers on their face suggest no overdeterrence. Regarded realistically,
however, they suggest some degree of underdeterrence.

3. Terry Stops

Under Terry v. Ohio (125) and its progeny, the police may detain a
suspicious person for investigation if they have what the cases call
"reasonable suspicion" to believe he is engaged in criminal
activity. If the courts have been reluctant to quantify probable cause,
they have been even less willing to quantify reasonable suspicion. The
officer is said to need "a reasonable suspicion supported by
articulable facts that criminal activity 'may be afoot
....'" (126) An anonymous tip corroborated only by police
observation of innocent details in the tip falls short of this standard.
(127) Presence on the streets in a high-crime neighborhood, coupled with
flight from the police on sight, is enough. (128) If the police are
justified in stopping the suspect, they may conduct a protective
pat-down search for weapons if specific facts are present to suggest
that the suspect might be dangerous.

The opportunity cost of these street encounters is relatively low.
The police are still present on the street, and if they hear gunfire or
someone shouting "Stop, Thief!" they can abandon their
speculative encounter and address the emergency. At the scene of their
deployment they produce the nonevidentiary benefits of a visible patrol
presence, but unless they actually stop people they will have no
evidentiary gains, unless they see an offense in flagrante. From a
crime-control standpoint, they have an incentive to stop and frisk the
most suspicious person in the area, regardless of just how suspicious
that individual happens to be.

Liability risk for Terry stops is also low. Because the governing
law is expressed as a standard ("reasonable suspicion") rather
than a rule (no entry of private premises without a warrant, consent, or
emergency), the qualified immunity defense protects all but the most
egregious violations. Damages from an encounter measured in minutes are
not likely to be large. So, as with warrantless searches, the primary
incentive to comply with the reasonable-suspicion standard is the
exclusionary rule.

If the police have enough evidence ex ante to make an arrest, they
have no need for the Terry procedure. There is a small probability that
the suspect will admit criminal activity. While there may be some
crime-control benefit from hassling suspected gangsters in public view
or dissuading the suspect from a planned but never consummated offense,
a major reason for these stops is the prospect of discovering drugs or
guns. The exclusionary rule's role here is definite but limited. If
the police act unlawfully they may lose their case, but the drugs or
guns will still be off the streets.

Like warrantless searches, Terry stops were hard to study before
the racial profiling controversy. The controversy has generated
considerable data about police practices, but it is difficult to gauge
the extent of police compliance with constitutional standards. For
example, reviewing police records to determine the presence of
reasonable suspicion or probable cause reveals the limitations of the
records themselves. Using this approach, the New York Attorney
General's office estimated that in a sample of more than 15,000
recorded Terry stops, 15.4% of the records failed to establish legal
grounds, and another 23.5% left unclear the legality of the police
actions. (129) It has been pointed out, however, that police often have
more information than time and energy to report, implying that in many
cases adequate grounds were present but unrecorded. (130)

Direct observations of police behavior can squarely address the
frequency of constitutional violations. Jon Gould and Stephen Mastrofski
conducted an observation study of police search practices in a
medium-sized city. (131) They identified 115 searches and coded them as
constitutional or unconstitutional, with doubtful cases evaluated by a
committee composed of one former judge and two former prosecutors. Gould
and Mastrofski concluded that thirty-four (30%) of the searches were
illegal, and that in thirty-one of these cases the suspect was neither
arrested nor cited, so that the case would never enter the criminal
justice system. (132) Of the 115 searches in the sample, forty-four were
pat-downs under Terry and seventy-one were "full searches" or
searches for evidence. Twenty (45.5%) of the pat downs were deemed
illegal, as were fourteen (19.7%) of the searches for evidence. (133)

This approach, however, also has at least two weaknesses. The first
is that it is time-intensive and therefore costly, meaning that limited
sample sizes may not produce representative results. Gould and
Mastrofski, with a substantial team and a National Institute of Justice
grant, generated a sample of merely 115 cases from a single
jurisdiction. (134) The second is that in at least some cases,
reasonable observers may disagree about the legality of the police
actions. (135)

This Article's focus on hit rates has its own limitation,
i.e., the legality of a stop or a search does not depend on the result.
Hit rates, however, have two advantages. We now have access to some
large samples of data, and hit rates are more objective than
professional opinions about legality. Since compliance with the
reasonable suspicion standard in a large pool of cases would limit the
hit rate, hit rates offer an important item of evidence in measuring
compliance.

Using a larger sample of the reports reviewed by the New York
Attorney General's Office, a recent RAND study of more than 500,000
reported Terry stops by the New York Police Department
("NYPD") (136) found that only 10% of these stops resulted in
either an arrest or a citation. (137) The NYPD employs a particularly
aggressive version of community policing, and so we might expect the New
York City hit rate to be uncharacteristically low. If, however, we are
interested in the influence of Fourth Amendment remedies, then we are
similarly interested in how far an aggressive police department feels it
may go before the costs exceed the gains. The NYPD must therefore
believe that neither the exclusionary rule, nor the tort remedy,
eliminates the net benefits resulting from Terry stops with a 10% hit
rate. The reporting requirement that made the New York data possible,
moreover, increases OC for stops. We might well expect the hit rate to
be lower in jurisdictions with comparable police tactics but no
reporting requirement. Unless reasonable suspicion means something like
an outside chance, the remedial mix is underdeterring illegal Terry
stops.

The RAND data shed some interesting light on the frisk part of
stop-and-frisk. The data show that the police frisked only a minority,
roughly one-third, of those stopped. (138) This may be a reporting
artifact, but that seems improbable given that in the other two-thirds
of these cases the police took the time to fill out the form recording
the stop itself. The hit rate for these frisks is quite low, with the
recovery of some contraband occurring in 5.46.4% of frisks. (139) The
numbers vary a bit across racial groups, but, roughly speaking, 1% of
frisks across groups result in the recovery of a weapon. (140) Some
contraband was recovered in 6.4% of frisks of whites, 5.7% of blacks,
and 5.4% of Hispanics. (141) The recoveries were primarily of drugs:
"For every 1,000 frisks of black suspects, officers recovered seven
weapons, and, for every 1,000 frisks of similarly situated white
suspects, officers recovered eight weapons, a difference that is not
statistically significant." (142)

What can we learn from these numbers? The very low rate at which
the police recover weapons stands to reason. They face an immediate,
personal, and potentially catastrophic cost if the suspect resorts to
lethal resistance. The finding that the police are not frisking almost
every suspect stopped is somewhat surprising. In any event it seems that
if the police do fear armed resistance, the exclusionary rule is
unlikely to influence their behavior.

The substantive law makes weapons but not drugs fair objects of the
so-called protective search. If the exclusionary rule creates incentives
that trump officer safety, overdeterring justified frisks for weapons,
we would expect to see much higher hit rates for weapons. The six- or
seven-to-one ratio of drugs to weapons recovered might mean that the
police often frisk the suspect not because they subjectively fear for
their safety, but because they hope to discover illegal drugs.

The hit rate suggests that in practice "reasonable
suspicion" means about a one-in-ten chance of finding anything (and
a dramatically lower chance of finding one of the weapons that
theoretically justifies the "protective search"). This might
reflect either of two causes. One is that in ruling on suppression
motions, the judges, generally following the Supreme Court's
guidance, are willing to accept very little in the way of particularized
suspicion. If, for example, in the case Florida v. J.L., (143) the
police had added to the anonymous tip a furtive gesture or evasive
movements by the suspect, and characterized the locale as a high-crime
neighborhood, a suppression motion would very likely have failed.

If the 10% hit rate (with much lower hit rates once open-container
alcohol and personal-use marijuana violations are excluded) is really
consistent with the Supreme Court's stop-and-frisk jurisprudence,
the exclusionary rule is working fine in this context. It should be
recalled, however, that when Indianapolis police set up road blocks to
stop every vehicle, wholly without individualized suspicion, to perform
canine examination and sobriety checks, the hit rate was 9%. (144) If
"reasonable suspicion" means something more demanding, the low
hit rate in stop-and-frisk cases may be due to the prominence of
nonevidentiary reasons for aggressive patrol tactics, and/or judicial
reluctance to drop the exclusionary hammer.

The J.L. case is again illustrative. Whatever happened in court,
officers who get an anonymous tip that a kid is carrying a gun onto a
city bus are likely to intervene. If no weapon is found, practical
liability risks are next to zero. If a weapon is found, it will be
confiscated even if it is later suppressed. And even if "reasonable
suspicion" is dubious, if a weapon is found the courts may very
well admit the evidence too. In J.L., the Florida trial court granted
the suppression motion, but the state appellate court reversed. (145)
The Florida Supreme Court agreed with the trial court that the evidence
should have been suppressed, but two dissenters urged an exception that
would make a conclusory anonymous tip reasonable suspicion when the tip
alleges the possession of a firearm. (146)

If the first explanation, that "reasonable suspicion" is
an undemanding standard, is correct, the exclusionary rule might be
achieving close to optimal deterrence in stop-and-frisk cases. If the
second explanation is correct, the empirical evidence suggests under,
rather than overdeterrence.

4. Police Brutality

The worst forms of unconstitutional police misconduct--police
brutality--have no EVB and so the exclusionary rule has no direct
disincentive effect. Brutality does have a relatively high LC. There is
enough police brutality to doubt that the tort sanction is overdeterring
it (recall that when illegality is certain there is no risk of
overdeterrence). "The national average among large police
departments for excessive-force complaints is 9.5 per 100 full-time
officers." (147) However one regards the present
tort/crime/discipline remedial mix for police brutality, the
exclusionary rule debate is largely irrelevant to the brutality problem.
Abolition might signal carte blanche to the police and thereby encourage
brutality by implication. In a rational actor model, however, abolition
of the exclusionary rule would not change training or discipline with
respect to police violence.

5. Arrests

As with police brutality, the exclusionary rule has little to do
with police incentives. Evidentiary benefit is no consideration at all
in most arrests. Arrests are infrequently an instrument of investigation
and far more often the end-stage product. In theft cases, and
buy-and-bust drug cases, the police hope to find incriminating evidence
at the time of arrest. But the bulk of arrests reflect other police
incentives.

Warrants for nonappearance are a substantial fraction of arrests.
In flagrante arrests, whether for purse-snatching, public intoxication,
or solicitation of prostitution, are another substantial percentage.
Arrests to suppress immediate violence, especially domestic violence,
are yet another significant fraction. From a departmental perspective,
the expected value of arrests is almost all nonevidentiary. Either the
police already have the evidence they need, or the arrest is made for
social control purposes other than initiating a prosecution in court.

The exception is the so-called pretextual arrest, where the police
make an arrest because they have broader search powers incident to the
arrest than they have based on the probable cause or reasonable
suspicion standards. In these cases, rules that clearly limit the scope
of the search incident tend to discourage pretextual arrests when the
suspected evidence is outside the permitted zone of search, and to
encourage pretextual arrests when the suspected evidence is in that
zone.

The predicate arrest must be based on probable cause, but no
warrant is required except when the police need to force entry into
private premises to effect the arrest. We can look to case attrition
studies--studies of "lost arrests"--to see how many arrests
end in conviction, and thereby construct a sort of "hit rate"
for arrests. While the figures vary from jurisdiction to jurisdiction,
the figure generally accepted is that half of all arrests result in a
conviction and half do not. The most recent numbers are a little lower
than that. (148) That sounds very much like probable cause.

Whether too high, too low, or just right, current case attrition
figures probably are not due to the Fourth Amendment remedies mix. Tort
liability for false arrest is part of the cost side of the equation, but
drastically limited by qualified immunity. In some atypical cases--drug
cases and perhaps a few others--the police hope to discover some
evidence incident to the arrest, and in these cases the exclusionary
rule may have some influence as well. If this remedial mix were
over-deterring we would expect to see substantially lower case attrition
rates, i.e., we would expect the police to concentrate resources in
cases where probable cause is clear rather than borderline. It seems
more likely that Fourth Amendment remedies have negligible influence on
arrests, and that police behavior is explicable largely in terms of
opportunity cost.

When the police apply for an arrest warrant as part of an ongoing
investigation, the opportunity cost, in terms of lost police time,
resembles that of obtaining a search warrant, but is generally smaller.
Bench warrants are not sought by the police, and in any event most
arrests are not authorized by warrant ex ante. The opportunity cost of
an arrest is the time it takes for the police to find, subdue, and
transport the offender before handing him off to the court system's
lockup and write a report.

The opportunity cost of search warrants is measured in days. The
opportunity cost of an arrest is measured in fractions of an hour but is
still significant. If arrest serves neither immediate social control
purposes, nor initiates a promising prosecution, police administrators
have reasons to train the force to remain at work on proactive patrol or
investigating reported offenses.

6. Summary of the Evidence on the Overdeterrence Hypothesis

The evidence available suggests that the current remedial mix is
doing a passable job with respect to home invasions, where the rule-type
warrant requirement forces the police into the costly warrant process.
The evidence further suggests that, when the opportunity cost for
unlawful searches or seizures is low, the current mix is not adequately
deterring unlawful police actions governed solely by standards like
probable cause or reasonable suspicion. This should concern civil
libertarians, but there seems little cause to criticize the current
remedial mix for discouraging lawful searches and seizures.

The Hudson majority's concern with the exclusionary
rule's "substantial social costs" is at odds with the
overdeterrence thesis. Perhaps most telling is the frequency with which
the courts rely on exceptions to the exclusionary rule to admit evidence
obtained in violation of constitutional requirements. If the tort
sanction were deterring such violations, the exclusionary rule could not
exact those "substantial social costs," and there
wouldn't be a great deal of tainted evidence available under
exceptions to exclusion. There wouldn't be many Fourth Amendment
violations to support suppression motions. A judiciary that wanted to
eliminate the exclusionary rule without encouraging violations of the
Constitution would not do so de jure, but de facto, by crafting
effective alternative remedies that make exclusion too rare to care
about.

That course, exemplified by eliminating the judge-made qualified
immunity defense, really does run the risk of overdeterrence. Given the
prevalence of indemnification of individual officers, and the Supreme
Court's extensive recognition of bright-line rules, tort liability
sans immunity and sans exclusion might move us closer to optimal
deterrence. Given the disconnect between tort damages and the expected
gain from aggressive policing, we would also have to consider the
possibility that such a regime would either underdeter (if, for example,
low damages for arbitrary Terry stops gave police general search powers
of citizens on the streets) or over-deter (if extravagant juries brought
back awards high enough to discourage the police from acting in all but
clearly legal cases).

III. RIGHTS-BASED THEORIES OF THE EXCLUSIONARY RULE

Justice Ginsburg dissented in Herring. She argued that the
exclusionary rule was necessary to deter negligent record-keeping by the
police. More momentously, she criticized the deterrence-based
cost-benefit analysis the Court has followed since Calandra. Justice
Ginsburg embraced a "more majestic" understanding of the
exclusionary rule, an understanding that calls for suppression even when
there is little reason to expect deterrence of future Fourth Amendment
violations.

Justice Stevens, Justice Breyer, and Justice Souter joined Justice
Ginsburg's opinion, so the Calandra approach now hangs by a thread.
A change of view by one of the Justices in the Herring majority, or a
change in the composition of the Court, could produce a majority that
favors Justice Ginsburg's approach. Her approach therefore deserves
careful analysis.

That is less easy than it sounds, because Justice Ginsburg's
Herring dissent is both exceptionally brief and vague about just what
this "majestic" view entails. The Herring dissent devotes only
four paragraphs to criticizing the Calandra approach. The first
paragraph, quoting Justice Stevens's dissent in Arizona v. Evans,
declares that the Fourth Amendment "'is a constraint on the
power of the sovereign, not merely on some of its agents.'"
(149)

The second paragraph, quoting Potter Stewart, characterizes
exclusion as "'a remedy necessary to ensure that' the
Fourth Amendment's prohibitions 'are observed in
fact.'" (150) After a citation to a prominent article by Yale
Kamisar, (151) this paragraph goes on: "The rule's service as
an essential auxiliary to the Amendment earlier inclined the Court to
hold the two inseparable." (152) The paragraph ends with a
"see" citation to Whiteley v. Warden (153) and a
"cf." citation to the famous dissents of Holmes and Brandeis
in Olmstead v. United States. (154)

The specific citation to Whiteley is to pages 568-69, where the
Whiteley Court concluded that when police act in reliance on a wanted
bulletin from other police, the arresting officers lack probable cause
if the officers issuing the bulletin lack probable cause and the
arresting officers learned nothing new before the arrest. (155) The only
reference to the exclusionary rule is this sentence: "Therefore,
petitioner's arrest violated his constitutional rights under the
Fourth and Fourteenth Amendments; the evidence secured as an incident
thereto should have been excluded from his trial," followed by a
boiler-plate citation to Mapp. (156) This does not appear to add
anything to the integration/unitary transaction view announced in the
first paragraph.

The references to Brandeis and Holmes are even more puzzling.
Justice Brandeis's famous dissent in Olmstead followed the
then-controlling Boyd case. Boyd held that the Fourth Amendment forbade
any seizure of private papers, and that the Fifth Amendment forbade the
use of illegally-seized papers as evidence against their owner. (157)
The issue in Olmstead was whether private telephone conversations,
illicitly intercepted, should be treated like papers. Justice Brandeis
said that they were, in famous language. (158) But Boyd is dead.

Justice Ginsburg, presumably, is not calling for the return of
Boyd. In Justice Brandeis's view, Boyd calls for holding
unconstitutional any--repeat, any--surreptitious electronic surveillance
for law-enforcement purposes. (159) In any view, Boyd prohibits any
seizure of private papers, even under warrant, unless the papers qualify
as fruits, instrumentalities, or contraband. And while Boyd was
understood to protect nontestimonial physical evidence (once again
immune from seizure even pursuant to a valid warrant), Boyd did not
protect tools, fruits of crime, or contraband. An exclusionary rule
based on Boyd therefore would not reach guns or drugs, the very evidence
the Herring dissenters would have suppressed.

Justice Holmes dissented separately in Olmstead. Holmes supported
the Fourth Amendment exclusionary rule and himself had detached it from
the self-incrimination privilege in Silverthorne Lumber Co. v. United
States. (160) Silverthorne suppressed evidence obtained by an
unconstitutional search of a corporation. Corporations have no
self-incrimination rights under the Fifth Amendment. Holmes noted the
point, but then declared that "the rights of a corporation against
unlawful search and seizure are to be protected even if the same result
might have been achieved in a lawful way." (161) Silverthorne
speaks both the language of deterrence (admissibility "reduces the
Fourth Amendment to a form of words") and judicial integrity
("The essence of a provision forbidding the acquisition of evidence
in a certain way is that not merely evidence so acquired shall not be
used before the Court but that it shall not be used at all.").
(162)

Holmes took a clearer stand for judicial integrity in Olmstead.
Even if the Olmstead majority was right that wiretapping does not
constitute a Fourth Amendment "search," there was no doubt
that the interception in that case was a crime under state law. State
prosecution therefore offered at least a theoretical alternative to
exclusion for deterrent purposes. Without endorsing Brandeis's
constitutional argument, Holmes endorsed a version of the judicial
integrity theory, as follows:

For those who agree with me no distinction can be taken between the
government as prosecutor and the government as judge. If the
existing code does not permit district attorneys to have a hand in
such dirty business it does not permit the judge to allow such
iniquities to succeed. (163)

Dropping the inapposite invocations of Whiteley and Brandeis, the
second paragraph condenses to adding the authority of Holmes and Kamisar
to the first paragraph's announcement that the use of tainted
evidence is itself forbidden by the Fourth Amendment. The third
paragraph makes a different, consequentialist argument. Quoting Justice
Brennan's Calandra dissent, the Herring dissenters argue that
exclusion "'enabl[es] the judiciary to avoid the taint of
partnership in official lawlessness,' and it 'assur[es] the
people--all potential victims of unlawful government conduct--that the
government would not profit from its lawless behavior, thus minimizing
the risk of seriously undermining popular trust in government."
(164)

Granting that if admission of the evidence necessarily implicates
the court in a violation of the Fourth Amendment the court should refuse
the evidence, what does this consequentialist point add to the case for
the exclusionary rule? In a fascinating role-reversal, we see the
defenders of civil liberties putting forth a sort of broken-windows type
of deterrence argument. If the courts approve Fourth Amendment
violations, the moral message will encourage illegal behavior by both
police and citizens.

Clearly enough this is an empirical claim, and similarly clear is
that it is put forth as an article of faith rather than a proposition to
be tested empirically. Even those who endorse this sort of systemic
deterrence idea, however, might well lose their faith when they consider
that one consequence of the exclusionary rule has been the proliferation
of police perjury. No one can quantify it, but there is widespread
belief that police not infrequently testify untruthfully at suppression
hearings and that judges not infrequently credit (I do not say
"believe") their testimony. (165)

If exclusion is thought to encourage police to turn square comers,
and the most immediate reaction to this moral message is perjury, one
might be inclined to rethink the sending of this moral message.
Likewise, citizens who see evidence admitted based on unlikely police
testimony will be receiving a very different moral message than the one
the Herring dissenters want to transmit.

At one point I took the view that police perjury reflected the
failure of typical trial judges to meet the standard set by Holmes and
Brandeis. That, however, is an impossible standard to expect. Given the
judges we are likely to have, it is a fair point against the
exclusionary rule that the release of an obviously guilty offender is so
unpalatable that judges will resort to unsavory expedients to avoid that
result.

The final paragraph of the Herring dissent's critique of
Calandra tersely but correctly asserts the inadequacy of other remedies
for Fourth Amendment violations. If we strip away the ghostly echoes of
Boyd and the problematic moral-message argument, Justice Ginsburg's
case for a "more majestic" view of the exclusionary rule
reduces to the argument that admitting tainted evidence should be
regarded as forbidden by the same constitutional provision that
prohibits the search.

This position has distinguished defenders. (166) It also has a
variety of related weaknesses. First, it does not speak to illegal
searches or arrests that produce no evidence (to which, for simplicity,
I will refer to as searches of the innocent, even though that label is
not perfectly accurate). Second, it does not account for alternative
remedies, including the application of an exclusionary rule designed
solely for deterrent purposes. Third, all such theories seem
inconsistent with the qualified immunity defense to tort suits against
police for Fourth Amendment violations. Fourth, unitary transaction
theories misunderstand the nature of the rights protected by the Fourth
Amendment.

Begin with the case of the innocent search victim. On a
unitary-transaction account, the courts are just as involved in an
unfruitful illegal search as in a fruitful legal one, as the purpose of
the search is to discover admissible evidence. I assume that equity and
integrity can be satisfied by something other than exclusion. Otherwise
the government would need to do something like offer innocent victims of
illegal searches the right to pull pending indictments against third
parties out of a hat to be dismissed. If the government has done for the
guilty whatever is enough to satisfy its duties to the innocent, there
seems no reason to go further and suppress the evidence against the
guilty.

Suppose the police, without a warrant, consent, or exigency, break
into the apartment of A and B. In A's bedroom they find nothing; in
B's bedroom they find illegal drugs. A's only judicial remedy
is a tort suit. If that suit satisfies Fourth Amendment requirements for
the innocent, why is it not enough for the guilty?

The problem of innocent search victims necessarily leads to
consideration of alternative remedies. To take an extreme example,
suppose again that the police find illegal drugs during an illegal
search. Now suppose (this is counterfactual but illuminating) that the
responsible officers have been charged criminally, convicted, and sent
to prison before the court rules on the suppression motion. (167) Has
the government not done enough to cleanse its hands and dissociate
itself from the unlawful search? Has it not done enough to express its
disapproval of its agents' conduct? It has done all it could do, if
the defendant were innocent. Must it do even more for the guilty?

Familiar criminal-law principles of complicity suggest otherwise.
Suppose A says to B: I will pay you $100 for every illegal weapon you
turn into me. If, however, you steal the guns, or break into private
premises for them, I will still pay you the money, but I will also
prosecute the case to the fullest extent of the law. If B commits a
crime to collect guns for the buyback program, is A complicit? If A is
in earnest and credible, A neither intends for B to commit the offense,
nor, all things considered, encourages it or aids it.

Up until Boyd in 1886, U.S. courts appear to have upheld the
common-law rule that illegality in the search or the seizure did not bar
proof at a criminal trial. (168) Indeed, it was thought a point against
exclusion that this would require going into a "collateral
issue!" (169) For the first ninety years of the Republic, search
and use were not thought of as a unitary transaction, and judicial
integrity was not thought to require rejecting tainted evidence in
court. Instead, what we think of as the "alternative" tort
remedy was supposed to be the main, and quite adequate, relief for
illegal search and seizure. The atrophy of the tort remedy indeed
requires some new remedy with deterrent power. The claim that the Fourth
Amendment itself requires exclusion as a natural or inevitable
component, however, is a modern contrivance.

Nondeterrent theories have a further weakness: they conflict with
the qualified-immunity defense to tort actions under Bivens and 42
U.S.C. [section] 1983. Suppose in our initial hypo the police applied
for a warrant, and a judge mistakenly concluded that the affidavit
established probable cause. Suppose A, the innocent roommate, now brings
suit, and the officers move for summary judgment, claiming the immunity
defense. If the court grants judgment for the defendant, as the law now
requires, nothing will happen about the illegal search of A's room.
The court will turn the innocent victim of a constitutional violation
away from the courthouse. If equitable principles or judicial integrity
require suppressing B's drugs, regardless of the consequences, they
also point toward awarding A damages, regardless of the consequences.

A robust tort remedy risks genuine overdeterrence. So the immunity
defense is understandable; (170) it is just not understandable from the
standpoint of equity or judicial integrity.

The final point, implicit in the first two, is that Fourth
Amendment rights do not trump substantive laws against possessing drugs
or weapons. Again, suppose the police enter and search the apartment of
A and B without a warrant. Suppose the police find drugs in B's
room but not in A's. A and B sue the police for damages. Should
B's recovery be higher than A's? Surely his consequential
damages are greater. Yet it seems wrong on principle to say that
criminals enjoy greater Fourth Amendment rights than law-abiding
citizens, or that the Fourth Amendment creates a constitutional right to
commit murder in soundproof rooms. (171)

Given that we do not return contraband, or increase damages for
illegal searches that discover contrand, the exclusionary rule really is
detached from the prior search. The defendant is allowed to suppress
because only in this way can the court protect the Fourth Amendment
rights of persons unknown, who would suffer constitutional violations in
future cases if the court received the evidence. As in the classic
third-party standing cases like Craig v. Boren or Barrows v. Jackson,
(172) assertion of the claim by the right-holder is impracticable. The
tort action has atrophied, and there is no sentiment in the court, or in
legislatures, for revitalizing it.

Deterrence is a perfectly sound explanation for the exclusionary
rule. The emergence of professional police forces in the nineteenth
century depended on immunity from traditional tort liability, whether
that immunity was recognized de jure or de facto. With the atrophy of
the trespass and false-arrest actions the founders had known, police
behavior was virtually lawless. The Fourth Amendment, like most
constitutional provisions, says nothing about remedies. If the federal
courts have a duty to enforce a constitutional provision, and no
adequate statutory or common-law remedies exist, then the federal courts
also have discretion to fashion an appropriate mix of remedies.
Defenders of this view include Roger Traynor, Potter Stewart, and
Anthony Amsterdam. As we have seen, exclusion does encourage police
compliance and, in all probability, does not overdeter in the
normatively appropriate sense of the term.

As Professor Amsterdam observed long ago, (173) and Professor
Alschuler noted in analyzing the causation issue in Hudson, (174)
deterrence is not incompatible with suppressing evidence that was
obtained without violating the rights of the instant defendant. Indeed,
there need be no violation of the Fourth Amendment in the instant case
at all. (175) For deterrent purposes the correct inquiry into causation
is prospective, not retrospective. Target standing is just as logical as
any other application of the exclusionary rule. (176) Professor
Amsterdam's proposal to exclude drugs found during legal frisks for
weapons under Terry is doctrinally more radical but likewise a logical
disincentive to illegal stops and frisks. (177)

Overdeterrence again poses a countervailing consideration. Suppose
the government were required to dismiss fifty cases whenever the defense
won a suppression motion. This would deter like hell, and not all for
the good. The government would then train the police force to avoid all
but the most clearly legal searches.

Consider another hypothetical case, this one based on Walder v.
United States. (178) Suppose the police arrest D without probable cause,
and find illegal drugs on his person in the search incident to the
arrest. D successfully moves to suppress and the case against him is
dismissed. A year later, D is arrested after buying illegal drugs from
an undercover agent. D claims entrapment. The government offers to prove
predisposition with proof of the seizure the year before.

In this case, the government already has lost one case against the
defendant and the defendant has not done anything wrong in defending the
second case (unlike Walder, who perjured himself on the stand at the
second trial by claiming that he had never had anything to do with
drugs). Do equitable principles or judicial integrity require excluding
the evidence in the second case? My intuition is that there is no good
reason to exclude the evidence in the second case.

Another excellent test case is Calandra. (179) Following the
illegal search, Calandra was called to testify before a grand jury. When
he claimed Fifth Amendment immunity, the government issued a
transactional immunity order. He nonetheless asserted a Fourth Amendment
right not to answer questions when the factual predicate for the
questions was the prior illegal search. Just as in Walder, the
government lost the case that the tainted evidence might have made.
Going further with exclusion would not have restored the privacy lost
during the illegal search, nor would it have discouraged subsequent
violations.

We have the exclusionary rule not because it is a necessary remedy
for Fourth Amendment violations, but because it is the possible remedy
with the least combined risk of underdeterrence and overdeterrence. Many
remedies, like liquidated punitive damages, could deter (and satisfy
other remedial objectives such as judicial integrity), but only at the
risk of overdeterrence. Other remedies can be modified to avoid
overdeterrence, but only by making them toothless (the immunity defense
to tort suits is illustrative).

In search-for-evidence cases, exclusion comes tolerably close to
setting the government's expected gain from illegal searches at
zero, and thus rationally mediating the risks of over and
underdeterring. This account is convincing, so far as it goes, but it
neglects the liberal critique of the exclusionary rule for being less
effective than a statutory alternative and for encouraging judges to
twist both the facts and the law to avoid freeing the manifestly guilty.
The traditional exclusionary rule is not optimally deterring warrantless
police actions with low opportunity costs, such as violations of the
stop-and-frisk rules under Terry v. Ohio. This reinforces criticisms of
the exclusionary rule made by those to the left of the Hudson and
Herring majorities, such as Judge Calabresi (180) and Professor
Slobogin. (181) Despite hostility to the exclusionary rule, and any
number of proposals for reform, legislatures have not acted to provide
alternative remedies. (182)

In a prior article I argued for giving judges the option of
suppressing evidence contingent on the failure to pay damages. (183)
This approach might overcome the psychological disadvantage of the
exclusionary rule without risking overdeterrence. If the entity
employing the police regarded the damage award set as the alternative to
exclusion as excessive, it could acquiesce in exclusion. Judges,
however, probably would be more willing to grant suppression motions, on
both the facts and the law, if they knew that the government had an
escape hatch. Presumably the government would be most willing to pay
when the tainted evidence implicated especially dangerous offenders.

The contingent exclusionary rule concept bypasses many of the
weaknesses of traditional tort suits, but a different procedural vehicle
by itself cannot solve the valuation problem that explains why judges
and legislatures have permitted the atrophy of the tort remedy against
police. Suppressing evidence contingent on the failure to pay damages
thus takes a different route to the same dead end as traditional tort
remedies. If the judges set damages too low, the government would always
pay the damages, leading to a world much like the one that prevailed
before Mapp. If the judges set damages too high, the government would
always choose suppression, and contingent exclusion would have changed
very little besides adding a layer of procedural complexity.

What if, however, the government responded to a successful
suppression motion by pointing to specific remedial steps, such as a new
training program, a record-keeping program for stop-and-frisk or traffic
stops, or disciplinary actions against the responsible officers such as
reprimands, reassignments, demotions, or suspensions? In this scenario,
the threat of suppression might deter at least as effectively as the
executed threat. I call the basic idea "virtual deterrence."

IV. VIRTUAL DETERRENCE

As we have seen, a rational police agency will change its
operations to reflect the ways the exclusionary rule changes its
incentives. The very existence of the rule encourages the agency to
conduct training programs in Fourth Amendment law, and to monitor and
discipline officers. When the courts grant suppression motions, this
reinforces the general incentive and provides information to the force
about that specific incident.

What, exactly, do we want the police agency to do in response to
successful suppression motions? That depends on the nature of the Fourth
Amendment violation. If the officers did not know the limits on their
authority, we want their employer to train them, and others with similar
duties, so that they do understand the law. (184) Mandatory retraining
may also have a punitive effect; think about traffic school as a
sentence for driving offenses. If the officers knew the law and broke it
deliberately, we want the force to impose some sort of disciplinary
sanction. (185)

Sanctions against the offending officers have familiar purposes. We
want to deter these officers, specifically, from repeating their
misconduct; we want to deter other officers, generally, from similar
behavior; and when discipline takes the form of reassignment or
dismissal, we want to incapacitate the individual officers from future
transgressions.

The present arrangement relies on the police agencies themselves to
estimate the levels of training and discipline that will maximize the
value of the institution's resources. If the police were not
trained and disciplined with respect to constitutional standards at all,
the force would lose many cases that might have been made with better
police practices. On the other hand, resources spent on police training
are resources taken from other uses such as proactive patrol, and
officer sanctions may induce undue passivity. As we have seen, properly
understood, there seems now to be more underdeterrence than
overdeterrence of Fourth Amendment violations. (186)

A. Virtual Deterrence: The Basic Idea

Suppose that present exclusionary-rule practice were modified by
bifurcating the substantive Fourth Amendment question and the remedial
question. If the court hearing a suppression motion found a violation of
the Fourth Amendment, it might be required to consider the specific
steps, undertaken by the police department and/or the prosecutor's
office, by way of training and/or discipline, to prevent recurrence of
the violation. If the court concluded that these measures were adequate
and reasonable, it could admit the evidence. At least in theory, virtual
deterrence might function as well as (perhaps even better than) the
exclusionary rule, but also might cash in on the government's
evidentiary windfall without risk of overdeterrence.

To begin with the overdeterrence point, if the employing entity
concluded that the specific remedial measures demanded by the court
called for an undue commitment of scarce resources, or threatened
individual officers with undue incentives for passivity, these executive
branch officials could refuse to undertake the remedial measures (and
thereby accept some responsibility for the loss of evidence that would
then result). The government could not be made worse off than it stands
under the order suppressing the evidence.

As for the adequacy of the specific remedial measures, it is of
course only a predicted consequence of exclusion that police departments
undertake such measures now. If the linkage between remedial measures
and exclusion is simply one of the incentives, suppressing the evidence
after the remedial measures have been taken makes no sense. Indeed, in a
case like Herring, virtual deterrence improves on both the majority and
the dissent. The majority sacrifices any incentive to reform for the
sake of the conviction. The dissent sacrifices the conviction for the
sake of a signal it cannot guarantee leads to reform. Virtual deterrence
demands actual reform from the government, and would stand a decent
chance of getting it.

If the government already has taken the steps we want exclusion to
encourage, the exclusionary rule has served its purpose by a threat that
need not be executed. Recall the hypothetical case of the suppression
motion made by a defendant after the transgressing officers have been
prosecuted and jailed. Another helpful analogy is to practice under
Federal Rule of Evidence 407, (187) which bars proof of subsequent
remedial measures to prove tort liability. The rule is designed to avoid
deterring tortfeasors from taking steps to reduce the likelihood of
future accidents. (188) Accordingly, it does not bar plaintiffs from
proving remedial measures undertaken before the accident giving rise to
the instant suit. (189) Like Rule 407, virtual deterrence welcomes
relevant evidence as soon as the remedial measures that exclusion is
intended to encourage have in fact been implemented.

For purposes of illustration (as well as to show that virtual
deterrence does not depend on the court's particular jurisdiction
vis-a-vis the locus of the Fourth Amendment violation or the
investigating officers), reconsider Herring. Bad records in Dale County
caused officers in Coffee County to make a groundless arrest. The fruits
of the search incident to that arrest were the basis of prosecution in
federal district court.

Under current law, the magistrate and the district judge had to
choose between suppression and doing nothing, and chose to do nothing.
Virtual deterrence offers a third option. Before accepting the
magistrate's recommendation, the district judge might have asked
the assistant prosecuting the case to submit an affidavit from the Dale
County Sheriff indicating what steps, if any, had been undertaken to
improve the record-keeping system that was causing arbitrary arrests. If
no such affidavit were forthcoming, or if in substance it said nothing
was going to be done, the judge should have granted the suppression
motion. But something probably would be done; the Alabama authorities
obviously wanted Herring put away. And if nothing were done, suppression
would convey to other offices that there was no law-enforcement
advantage in shoddy accounting.

B. Pros and Cons

There are two important and related advantages to virtual
deterrence. The first is that evidence would not be lost. It is a
mistake to treat the loss of the evidence as a cost distinct from the
costs of the Fourth Amendment. (190) But the loss of the evidence is a
cost. The Fourth Amendment commands that this cost be borne because the
benefits of protecting liberty and privacy in a pool of cases exceed the
costs of the evidence that thereby goes undiscovered.

The Fourth Amendment, however, once violated, cannot be complied
with retroactively. When the veil of privacy is pierced in a single
case, it is no longer part of a pool. What the Fourth Amendment protects
is liberty and privacy, not immunity from the substantive criminal law.
Suppose D is driving home drunk, and is at fault in a collision with a
car driven by P. P, it turns out, has just burgled D's house, and
the collision forces open P's trunk, revealing D's computer
and flatscreen television.

If law could, it would undo the injuries and the damage. It cannot,
so D owes P compensation for his injuries and the damage to his vehicle.
D also is subject to criminal prosecution for purposes of general
deterrence and possible reformative treatment or education. Surely,
however, D is entitled to the fortunate recovery of his own possessions.
And P, once out of the hospital, will be prosecuted for burglary.

Victims can be compensated, and police can be deterred. That is all
that law can do. At least that is all it can do for the innocent, and it
should not do more for the guilty. If due steps are taken to ensure
compliance in the future, the court and the executive authorities have
satisfied their constitutional obligations in response to a Fourth
Amendment violation. Defendants would not lose their right to tort suits
to compensate them for the loss of their legitimate liberty or privacy
interests. The guilty would have the same remedies as the innocent.

The second advantage relates to the first. If a ruling on the
substantive Fourth Amendment question did not automatically trigger
suppression, but only left the ball in the executive's court to
propose appropriate remedial measures, judges would be less biased
against holding police action illegal. Evasions and fabrications would
no longer be necessary to avoid the escape of the guilty.

For low-cost police practices with substantial nonevidentiary
benefits, such as stop-and-frisk, the exclusionary rule is only a weak
deterrent. Nonetheless, to ensure the admissibility of evidence in
particular cases, especially high-value cases, the executive authorities
might agree to systemic reforms, such as record-keeping of the New York
type, that the traditional exclusionary rule has not encouraged. Virtual
deterrence might produce a higher measure of compliance with
constitutional requirements than the current exclusionary rule.

There are at least two problems with virtual deterrence. The first
is whether the defense would still have incentives to litigate
suppression motions. If the government routinely proposed a standard
one-hour retraining session for the officers involved, and this were
accepted by the courts, then the effect of the proposal would be to
abolish the exclusionary rule de facto. The adequacy of the
government's proposed remedial measures would be determined in the
first instance by the same trial judges who currently grant a
significant number of suppression motions, and appealable to the same
courts that maintain the exclusionary rule, so that outcome seems
unlikely.

It seems more likely that the judiciary would welcome the option of
protecting Fourth Amendment rights without suppressing evidence. These
are the same judges we trust with other constitutional rights. They
likely would insist on steps the government declines to take often
enough to induce defendants to continue making suppression motions.

The remaining problem for virtual deterrence is monitoring
compliance. The rules of criminal procedure do not provide for consent
decrees! Yet the gist of virtual deterrence is to convert the
traditional suppression motion into a kind of institutional reform
litigation. Suppose the court finds that the government's proposed
remedial steps are adequate. How does the court verify compliance?

A representation that the individual officers responsible for the
violation will undertake ten hours of retraining might mean, in
practice, that the officers spend ten hours at a sports bar grousing
about the judge. Reassignment might mean, in practice, reassignment to a
choicer post. Suspension might mean, in practice, a paid vacation.
Reprimands may be accompanied by invisible--but very real--asterisks.

These problems are real, but not entirely insurmountable. For
example, if additional training were administered by persons or
institutions outside the police organization, such as the
prosecutor's office, the judges themselves (perhaps retired, to
avoid any possible conflicts), or law professors (education might be a
two-way street in that variation!), the instructing party could verify
the participation and cooperation of the police.

Direct sanctions typically require a formal process by which public
employees can appeal some decision of the employer. (191) The labor-law
process creates a record that would enable monitoring. That process
takes time, and it might result in factual findings different from those
made by the criminal court that suppressed the evidence. The suppressing
court could accept the government's undertaking even though the
disciplinary steps might be undone by the labor-law process, or it might
insist on a final determination of the disciplinary matter before
admitting the evidence. In short, monitoring would be a challenge that
could be addressed only with some increase in procedural complexity, but
it is not a decisive objection to virtual deterrence, given the
advantages of the new approach.

C. The Bottom Line on Virtual Deterrence

In two situations, the problems of defense incentives and
monitoring compliance might nonetheless leave intact a very good case
for virtual deterrence. The first of these is grafting the
virtual-deterrence idea onto proposals for recognizing an exception to
the exclusionary rule when the charged offense is especially grave.
(192) These are relatively rare to begin with, and they now generate
strong pressures to nullify the exclusionary rule by such moves as
crediting implausible police testimony or finding inevitable discovery.

In a homicide case like Massachusetts v. Sheppard (193) or a major
drug case like United States v. Bayless, (194) a judicial option to
declare the search illegal but accept an official commitment to
undertake additional training for the individual officers or the force
generally would probably yield higher compliance with the Fourth
Amendment than now prevails. It could not overdeter as the government
could decline the conditions and accept suppression. With decades in
prison at stake, defense attorneys would still move to suppress. The
court's conditions might be unacceptable to the government, and the
adequacy of those conditions could be an issue on appeal.

The second situation includes categorical exceptions recognized by
current law that permit use of tainted evidence in the government's
case-in-chief. The current exceptions to the exclusionary rule are
predicated on the assumption that exclusion is either unnecessary or
futile from the standpoint of incentives for compliance. At least when
the theory is that there are countervailing incentives favoring
compliance, so that exclusion is not necessary, it makes sense to
require the government to prove the remedial steps it has taken before
the court receives evidence under the existing exceptions. Consider
three such categorical exceptions: standing, good faith, and inevitable
discovery.

In the standing context, the search victim's right to suppress
is said to provide adequate deterrence, even when, as in United States
v. Payner, the agents deliberately violated the victim's rights
with the purpose of exploiting the standing doctrine to incriminate the
target. (195) But why speculate about adequate deterrence, as opposed to
inquiring directly into what steps the government has taken to prevent
recurrence of the illegality? Remedial measures are something that can
be documented. If the government takes the position that adequate
deterrence has been achieved, it should be able to point to the steps it
has taken. In "good faith" cases this might call for
additional training; in "bad faith" cases where the police
knowingly broke the rules it might call for disciplinary sanctions.

Inadequate monitoring is no objection here, because we are
comparing virtual deterrence, with at least some representations and
documentation, to assumed deterrence, with no representations or
documentation at all. Likewise, current law gives the defense no
incentive to raise constitutional jus terti claims, regardless of how
flagrant the government's misconduct may be.

The good-faith exception for the fruits of erroneously-issued
warrants does not result in underdeterrence, because the opportunity
costs of search warrants give the police very strong incentives to
comply with the probable cause requirement quite aside from the risk of
lost evidence. (196) When, however, the police rely on faulty records,
whether kept by the courts, as in Evans, or by the police themselves, as
in Herring, there is no similar disincentive against casual
record-keeping practices that increase the scope of police power. (197)
In Herring, for example, it appears that the police were bent on pinning
whatever they could on one of the usual suspects and asked about
outstanding warrants for the purpose of searching Herring's car
incident to arrest.

The Herring majority appears to take the view that Herring was
illegally arrested but that this constitutional violation is too
trifling to merit any remedial action whatsoever. If the premise that
the arrest was illegal is true, the conclusion seems impious. At the
least, before admitting the evidence, the court hearing the suppression
motion ought to inquire about what steps have been taken to prevent
recurrence. If the answer is "none," the case can hardly be
classified as one of good faith.

Herring illustrates one positive potential of virtual deterrence.
Like dry-hole Terry stops, arrests based on bad-arrest records typically
do not result in evidentiary fruit. When, however, the police get really
lucky, the exclusionary rule gives the judiciary some systemic leverage.
Conditioning the admissibility of the evidence against Herring on
improved record-keeping procedures might have induced administrative
improvements that would have prevented the illegal arrests of many
innocents. Likewise, attaching strings to the admissibility of the
massive drug seizure in Bayless could have led to systemic changes like
record-keeping or reevaluation of police doctrine and training regarding
stop-and-frisk generally. If the reforms demanded by the judiciary are,
in the judgment of law enforcement officials, not worth the resources or
the incentive to passivity, the government could acquiesce in the
suppression order.

The inevitable discovery is thought to be justified because not
admitting tainted evidence that would have been lawfully discovered
anyway "would put the police in a worse position than they would
have been in if no unlawful conduct had transpired." (198)
Deterrence does not suffer because "[t]he need to adduce proof
sufficient to discharge its burden, and the difficulty in predicting
whether such proof will be available or sufficient, means that the
inevitable discovery rule does not permit state officials to avoid the
uncertainty they would have faced but for the constitutional
violation." (199) If inevitable discovery were factually
transparent the doctrine might make sense. The risk is that courts will
find inevitable discovery on dubious facts to avoid suppressing
evidence, especially in serious cases. The availability of the virtual
deterrence option in serious cases might encourage a more skeptical
attitude toward inevitable discovery claims. The Supreme Court itself,
for instance, might reconsider the question whether the preponderance
standard, rather than the clear-and-convincing standard, ought to apply.
(200)

In sum, virtual deterrence might cut the albatross of hard cases
from the neck of judges ruling on suppression motions. In typical cases
involving drug possession or low-level dealing, the idea is probably not
worth the additional procedural complexity. In two kinds of cases,
however, virtual deterrence might come closer to optimal deterrence than
current doctrine. In major cases, the de jure application of the
exclusionary rule is often nullified de facto. In standing cases, and
good faith cases outside the warrant context, the exclusionary rule does
not apply de jure now, based on speculative calculations of its
deterrent impact. In both types of cases, virtual deterrence might spur
remedial steps when none now occur, and it might also encourage more
judicial enthusiasm for the Fourth Amendment rights of the innocent, who
rely on the guilty to regulate the police.

CONCLUSION

The "new" exclusionary rule debate has nothing new in it.
The current Supreme Court majority subscribes to a normatively unsound,
and empirically unsupported, concept of overdeterrence. The Herring
dissenters invoke a conception of judicial integrity that mistakes the
nature of Fourth Amendment rights by demanding more for the guilty than
is due to the innocent.

Rigorous application of the normatively sound view of optimal
deterrence of Fourth Amendment violations calls for a different analysis
and, probably, very different results in the Calandra line of cases.
Justice Ginsburg's dissent suggests that this kind of rigor
might--just might--return to the Supreme Court, but transferring that
rigor to the courts hearing suppression motions is a less likely
contingency.

If the point to exclusion is deterrence, it makes sense to ask what
remedial steps the government has taken in response to a violation
before suppressing the tainted fruit. For administrative reasons that
process is probably not worth undertaking in typical cases. When,
however, the government admits illegality but offers the evidence anyway
on the theory that it has incentives to take remedial steps besides
suppression, the courts ought not to accept incentives when proof of
concrete remedial steps can be demanded. When the tainted evidence
implicates the accused in especially serious criminality, conditioning
admissibility on concrete remedial steps seems more faithful to the
Constitution, and to good sense, than conditioning admissibility on
implausible testimony or far-fetched substantive interpretations.

(3.) Id. at 595 ("In addition to the grave adverse consequence
that exclusion of relevant incriminating evidence always entails (viz.,
the risk of releasing dangerous criminals into society), imposing that
massive remedy for a knock-and-announce violation would generate a
constant flood of alleged failures to observe the rule....").

(4.) Id. at 591, 594, 596.

(5.) Id. at 610 (Breyer, J., dissenting) ("[T]he need for
deterrence--the critical factor driving this Court's Fourth
Amendment cases for close to a century--argues with at least comparable
strength for evidentiary exclusion here.").

(6.) Id. (Although reported violations are "legion,"
"the majority, like Michigan and the United States, has failed to
cite a single reported case in which a plaintiff has collected more than
nominal damages solely as a result of a knock-and-announce
violation").

(21.) 269 U.S. 20 (1925) (excluding cocaine discovered in a
warrantless search of the defendant's home; the defendant
disclaimed possession of the cocaine).

(22.) 338 U.S. 25 (1949).

(23.) 367 U.S. 643 (1961).

(24.) Id. at 652-53 (noting the "obvious futility of
relegating the Fourth Amendment to the protection of other
remedies").

(25.) Id. at 656 ("Only last year the Court itself recognized
that the purpose of the exclusionary rule 'is to deter--to compel
respect for the constitutional guaranty in the only effectively
available way--by removing the incentive to disregard it.'"
(citation omitted)).

(26.) Id. at 659.

(27.) Id. at 661 (Black, J., concurring) (questioning pure Fourth
Amendment theory but embracing that the use at trial of evidence
obtained in violation of the Fourth Amendment violates the Fifth
Amendment).

(28.) 211 U.S. 78 (1908) (finding that the Fourteenth Amendment
does not create a right against self-incrimination compelled by the
states).

(29.) 332 U.S. 46 (1947) (affirming that the Fourteenth Amendment
does not create a right against self-incrimination compelled by the
states).

(30.) 378 U.S. 1 (1964) (finding that the Fourteenth Amendment does
create a right against self-incrimination compelled by the states).

(31.) 381 U.S. 618 (1965) (holding that Mapp did not apply to cases
that had become final on direct review at the time of that decision).

(32.) 394 U.S. 165 (1969).

(33.) See id. at 174-75 ("The deterrent values of preventing
the incrimination of those whose rights the police have violated"
is an adequate remedy; further deterrence from third-party standing is
unjustified).

(37.) See Gouled v. United States, 255 U.S. 298, 309 (1921) (Under
Boyd and Weeks, search warrants "may be resorted to only when a
primary right to such search and seizure may be found in the interest
which the public or the complainant may have in the property to be
seized, or in the right to the possession of it, or when a valid
exercise of the police power renders possession of the property by the
accused unlawful and provides that it may be taken." (citing Boyd
v. United States, 116 U.S. 623, 624 (1886))).

(38.) See, e.g., Giles v. United States, 284 F. 208 (1st Cir. 1922)
(ordering that liquor seized under a defective warrant be excluded from
evidence and returned to the defendant).

(39.) Katz v. United States, 389 U.S. 347 (1967) (finding the use
of a microphone planted on a telephone booth, owned by a telephone
company, to be a "search" of the suspect when used to
eavesdrop on the suspect's telephone conversation).

(40.) Warden v. Hayden, 387 U.S. 294 (1967) (upholding seizure of
"mere evidence" including clothes worn by the suspect during
the alleged offense).

(41.) 392 U.S. 1 (1968).

(42.) 414 U.S. 338 (1974) (holding that a grand jury witness, given
transactional immunity, could be compelled to answer questions based on
evidence that the witness had previously successfully moved to suppress
against himself on grounds of unlawful search).

(43.) 493 U.S. 307 (1990) (holding that the defendant's
statement, obtained while he was illegally arrested, was inadmissible to
impeach testimony of X, a third-party defense witness).

(44.) 428 U.S. 433 (1976) (holding that the exclusionary rule does
not apply in a civil suit by the government for unpaid taxes in the
absence of any proof of federal participation in illegality).

(45.) 428 U.S. 465 (1976) (holding that state prisoners may not
relitigate suppression motions on petitions for federal habeas where the
state had provided the opportunity for full and fair litigation of the
Fourth Amendment claim).

(46.) 446 U.S. 620 (1980) (holding that the impeachment exception
to the exclusionary rule extends to contradiction of testimony elicited
by the prosecution from the witness-defendant on cross-examination).

(47.) 468 U.S. 897 (1984) (holding that evidence found pursuant to
a warrant issued despite the failure of the application to establish
probable cause will be admitted absent perjury in the supporting
affidavit, partisanship by the issuing judge, or patent inadequacy of an
application that well-trained police would recognize).

(48.) 468 U.S. 981 (1984) (holding admissible evidence of homicide
discovered by search authorized by a modified form narcotics warrant
that was not modified to particularly describe the evidence sought, but
which was particularly described in the officer's warrant
application).

(49.) 480 U.S. 340 (1987) (holding the fruits of search authorized
by an unconstitutional state statute admissible where the law
enforcement officer's reliance on the statute was objectively
reasonable).

(50.) 514 U.S. 1 (1995) (holding admissible fruits of search
incident to arrest based on an erroneous judicially-maintained record of
outstanding warrant).

(51.) See, e.g., Leon, 468 U.S. at 918 (exclusion might encourage
police to scrutinize applications and warrants to prevent judicial
errors, but "we find such arguments speculative"); Stone v.
Powell, 428 U.S. 465, 487-88 (1976) ("'We therefore decline to
embrace a view that would achieve a speculative and undoubtedly minimal
advance in the deterrence of police misconduct at the expense of
substantially impeding the role of the grand jury.'" (quoting
United States v. Calandra, 414 U.S. 338, 351-52 (1974))).

(52.) For example, in Kyllo v. United States, 533 U.S. 27 (2001),
Justice Scalia wrote the majority opinion characterizing thermal-imaging
of a private residence as a search. The technique would not have been a
trespass at common law, and although Justice Scalia noted criticisms of
Katz v. United States, 389 U.S. 347 (1976), he did not propose returning
to the trespass regime assumed by the founders.

(53.) 514 U.S. 927 (1995).

(54.) See Hudson v. Michigan, 547 U.S. 586, 604 (2006) (Kennedy,
J., concurring) ("In this case the relevant evidence was discovered
not because of a failure to knock-and-announce, but because of a
subsequent search pursuant to a lawful warrant. The Court in my view is
correct to hold that suppression was not required.").

(55.) See Hudson, 547 U.S. at 601 ("While acquisition of the
gun and drugs was the product of a search pursuant to warrant, it was
not the fruit of the fact that the entry was not preceded by
knock-and-announce.").

(56.) Id. at 594-99.

(57.) See id. at 596 ("Of course even if this assertion [that
without suppression there will be no deterrence of knock-and-announce
violations at all] were accurate, it would not necessarily justify
suppression.").

(58.) Id. at 599 ("Resort to the massive remedy of suppressing
evidence of guilt is unjustified.").

(63.) Id. at 599 ("There have been 'wide-ranging reforms
in the education, training, and supervision of police
officers.'" (citing SAMUEL WALKER, TAMING THE SYSTEM: THE
CONTROL OF DISCRETION IN CRIMINAL JUSTICE 1950-1990, at 51 (1993))). Dr.
Walker, on whose work the court relied, subsequently protested that
Justice Scalia had failed to appreciate the extent to which police
professionalism is a product of the exclusionary rule. See Samuel
Walker, Thanks for Nothing, Nino, L.A. TIMES, June 25, 2006, at M5:

Scalia's opinion suggests that the results I highlighted have
sufficiently removed the need for an exclusionary rule to act as a
judicial-branch watchdog over the police. I have never said or even
suggested such a thing. To the contrary, I have argued that the
results reinforce the Supreme Court's continuing importance in
defining constitutional protections for individual rights and
requiring the appropriate remedies for violations, including the
exclusion of evidence.

(65.) See Dripps, supra note 17, at 12 ("[B]ecause the very
great majority of crimes are not cleared by arrest there is good reason
to doubt that perfect police work would have secured convictions in very
many of those few cases lost to suppression motions." (footnote
omitted)).

(66.) See, e.g., id. at 19 ("They would, however, carry the
downside of effective deterrents: they would cause many crimes to go
unexposed, foster police perjury to defeat liability, and might chill
officers from conducting justified but borderline searches and
seizures.").

(67.) See Connor Hall, Letters of Interest to the Profession,
Evidence and the Fourth Amendment, 8 A.B.A.J. 646, 647 (1922) ("If
punishment of the officer is effective to prevent unlawful searches,
then equally by this is justice rendered inefficient and criminals
coddled. It is only by violations that the great god Efficiency can
thrive.").

(68.) See John C. Jeffries, Jr., Disaggregating Constitutional
Torts, 110 YALE L.J. 259, 263 (2000) ("Occasionally, localities can
be sued directly under [section] 1983 and held liable without proof of
fault, but the circumstances are very limited." (footnote
omitted)).

(69.) See id. at 267 ("[G]overnments routinely defend their
officers against constitutional tort claims and indemnify them for
adverse judgments.").

(72.) See id. at 767 ("The largest cases tend to involve
serious physical injuries or sexual misconduct by officers. The bigger
payments also occur when officers act based on racial prejudice or some
personal hostility to the plaintiff." (footnotes omitted)).

(73.) 471 U.S. 1 (1985) (holding the fatal shooting of a
non-dangerous suspect to be unreasonable seizure).

(75.) The actual facts are less sanitary. See Herring v. United
States, 129 S. Ct. 695, 698. Investigator Anderson was willing to phone
around the state looking for a reason to give Herring a toss. By strange
coincidence he received oral notification of an outstanding warrant,
actually rescinded but that "for whatever reason" was not
recorded as rescinded. Oddly enough, the timing simply forced the good
officer to arrest Herring not on the sidewalk, but in his truck, which
could be searched incident to arrest. If pretextual arrests were crimes,
there would be reasonable suspicion, if not indeed probable cause,
against Investigator Anderson. See id.

(79.) See id. at 711 (Breyer, J., dissenting) ("Distinguishing
between police recordkeeping errors and judicial ones not only is
consistent with our precedent, but also is far easier for courts to
administer than" the majority's approach). Justice
Breyer's reading of the case law is supported in Wayne R. LaFave,
The Smell of Herring: A Critique of the Supreme Court's Latest
Assault on the Exclusionary Rule, 99 J. GRIM. L. & CRIMINOLOGY 757
(2009).

(80.) See id. at 70-08 (Ginsburg, J., dissenting).

(81.) Part II of this article is a revised and expanded version of
a paper originally presented at the Lexis-Nexis Criminal Procedure Forum
held at Emory University School of Law in December 2008 (i.e.,
post-Hudson, but pre-Herring), and published with the other symposium
papers as Donald A. Dripps, The Fourth Amendment, the Exclusionary Rule,
and the Roberts Court: Normative and Empirical Dimensions of the
Over-Deterrence Hypothesis, 85 CHI.-KENT L. REV. 209 (2010).

(83.) See 3 WILLIAM BLACKSTONE, COMMENTARIES ON THE LAWS OF ENGLAND
208-15 ("If [the defendant] admits the fact [of a trespass], he is
bound to shew by way of justification, that some positive law has
empowered or excused him." (citing Entick v. Carrington, 19
Howell's St. Trials 1029, 1066 (C.P. 1765))). Reasonableness might
mitigate damages, but it would not negate liability. Blackstone says:
"the law ... determines the quantum of that satisfaction, by
considering how far the offence was wilful or inadvertent, and by
estimating the value of the actual damage sustained." Id. at 209.
Thus in Wilkes v. Wood, Wood had relied on the warrant issued by the
Secretary of State, but was nonetheless found liable in trespass for
damages of 1000 [pound sterling], a huge sum for the time. See 19
Howell's St. Trials 1154 (C.P. 1763).

(84.) See John C. Jeffries, Jr. & George A. Rutherglen,
Structural Reform Revisited, 95 CAL. L. REV. 1387, 1408 (2007)
("[A]ny attempt to extend damages liability to the case of
borderline error runs headlong into the judicial rationale for qualified
immunity. In no other context is the problem of overdeterrence--more
precisely, the problem of unintended deterrence of legitimate acts--more
keenly felt."). Contrary to Professor Slobogin's suggestion,
see Christopher Slobogin, Why Liberals Should Chuck the Exclusionary
Rule, 1999 U. ILL. L. REV. 363 (1999), good-faith immunity does not
eliminate the possibility of overdeterrence. If the expected sanction is
severe enough, the risk that the agency or court might erroneously find
the violation to be knowing, rather than in good faith, might deter many
justified police interventions. A damage remedy limited to compensation,
coupled with good faith immunity (basically the current [section] 1983
system, even if applied by an agency), avoids overdeterrence only by
tolerating substantial underdeterrence.

(85.) See Town of Newton v. Rumery, 480 U.S. 386 (1987).

(86.) The seminal authority for this proposition is Guido Calabresi
& A. Douglas Melamed, Property Rules, Liability Rules, and
inalienability. One View of the Cathedral, 85 HARV. L. REV. 1089 (1972).
In his debate with Professor Kamisar about the exclusionary rule, infra
note 180, Judge Calabresi made no use of the property/liability
construct, which tends to support the point in text.

(87.) See, e.g., Koon v. United States, 518 U.S. 81 (1996)
(reviewing the sentence imposed following the conviction of the police
officers accused of the Rodney King beating, which was recorded on
videotape).

(91.) See Eugene Kontorovich, The Constitution in Two Dimensions: A
Transaction Cost Analysis to Constitutional Remedies, 91 VA. L. REV.
1135, 1178-79 (2005) (distinguishing warrant-clause cases from
reaonableness-clause cases, and arguing that latter cannot be litigated
ex ante so that the Fourth Amendment should be understood as a liablity
rule). I find this analysis unsatisfying. For one thing, administrative
searches are analyzed under the reasonableness clause, not the warrant
clause, but are typically tested by suits for injunctive relief, as in
the drug testing and roadblock cases. More fundamentally, the
property/liability dichotomy does not tell us whether to choose
compensatory or deterrent measures for sanctions ex post. In, for
example, a police homicide case like Tennessee v. Garner, 471 U.S. 1
(1985), the only feasible remedy is ex post. It does not follow that the
amount of damages should be compensatory rather than punitive.

(93.) Writing in 1982, Judge Posner took the view criticized in the
text. Assuming that a search would enable a conviction society values at
$10,000, and that $100 would be adequate compensation for lost privacy
and the costs or repair,

[t]he much larger "fine" that is actually imposed will overdeter,
causing the government to steer too far clear of the amorphous
boundaries of the fourth amendment compared to what it would do at
the optimal fine level. The lawful searches that are forgone and
the convictions of the guilty which those searches would have
produced are social opportunity costs that the lower fine would
have avoided.

Yet most [exclusionary rule critics] do not argue that the
misconduct should be condoned or redefined as proper conduct; they
merely advocate the substitution of other sanctions that would not
involve excluding the fruits of the illegal search. If the
substitute sanctions were effective in deterring the misconduct,
there would not be any fruits, and so there would be no net gain
from the standpoint of accuracy in adjudication. Instead, the
critics should be advocating either that the standard for
determining whether a search is illegal should be redefined, and
specifically that searches should be deemed illegal only if the
evidentiary benefits do not equal or exceed the costs of the search
to the victim; or that the only sanction for an illegal search
should be a suit for compensatory damages. The latter approach
would require the police, in effect, to "buy" the fruits of their
"illegal" searches from the victims, which they presumably would do
when the evidentiary benefits exceeded the costs to the victim of
the search.

Richard A. Posner, An Economic Approach to the Law of Evidence, 51
STAN. L. REV. 1477, 1533 (1999). "The latter approach" is an
option only if the first approach is also taken, or if it is understood
as the same approach, once again masking substance as remedial. If the
tort damages reflected a constitutional component in excess
(traditionally very greatly in excess) of the cost of a cleaning crew
and new hinges, tort suits that promised recovery of constitutionally
adequate damages would cause the loss of the very evidence now excluded.

(94.) Herring v. United States, 129 S. Ct. 695,700 n.2 (2009)
("Justice Ginsburg's dissent champions what she describes as a
more majestic conception of... the exclusionary rule, which would
exclude evidence even where deterrence does not justify doing so.
Majestic or not, our cases reject this conception and perhaps for this
reason, her dissent relies almost exclusively on previous dissents to
support its analysis." (alteration in original) (internal quotation
marks and citations omitted)).

(95.) Ironically, the Hudson majority is very much on board with
Crawford v. Washington, 541 U.S. 36 (2004), a decision with more blood
on it in five years than Mapp has on it in nearly fifty. See, e.g., Tom
Lininger, Prosecuting Batterers After Crawford, 91 VA. L. REV. 747,
772-73 (2005) ("In Dallas County, Texas, judges are dismissing up
to a dozen domestic violence cases per day because of evidentiary
problems related to Crawford.").

(96.) See, e.g., United States v. Rabinowitz, 339 U.S. 56, 69
(1950) (Frankfurter, J., dissenting) (resentment against writs of
assistance and general warrants was "so deeply felt by the Colonies
as to be one of the potent causes of the Revolution").

(97.) See, e.g., ANDREW E. TASLITZ, RECONSTRUCTING THE FOURTH
AMENDMENT: A HISTORY OF SEARCH AND SEIZURE 1789-1868, at 106-225 (2006).

(98.) See, e.g., Franklin D. Roosevelt, President, United States of
America, Address to Congress (Four Freedoms Speech) (Jan. 6, 1941),
available at http://www.americanrhetoric.
com/speeches/fdrthefourfreedoms.htm (decrying the "new order of
tyranny" and stating that "[t]he American people have
unalterably set their faces against that tyranny").

(99.) See, e.g., NORMAN POLMAR & JOHN D. GRESHAM, DEFCON-2:
STANDING ON THE BRINK OF NUCLEAR WAR DURING THE CUBAN MISSLE CRISIS
(2006).

(100.) See, e.g., RICHARD RHODES, THE MAKIN6 OF THE ATOMIC BOMB 734
(1986) ("More recent estimates place the number of deaths [from the
atomic bomb dropped on Hirosbima] up to the end of 1945 at 140,000. The
dying continued; five-year deaths related to the bombing reached
200,000."); id. at 740-42 ("70,000 died in Nagasaki by the end
of 1945 and 140,000 altogether across the next five years, a death rate
like Hiroshima's of 54 percent.").

(101.) Cf Raymond A. Atkins & Paul H. Rubin, Effects of
Criminal Procedure on Crime Rates." Mapping out the Consequences of
the Exclusionary Rule, 46 J.L. & ECON. 157, 174 (2003) (finding
through an empirical study based on FBI Uniform Crime Reports data in
pre-Mapp-no-exclusion and pre-Mapp-exclusion states that "Mapp
increased crimes of larceny by 3.9%, auto theft by 4.4%, burglary by
6.3%, robbery by 7.7%, and assault by 18%"). When confronted by the
finding that states that adopted the exclusionary rule on their own
decreased the crime rate, the authors freely speculate about
self-selection. See id. at 171. It is no more of a reach to speculate
about self-selection in other ways. For example, law-and-order states
that did not exclude before Mapp might have been the first to make
narcotics an urgent priority shortly thereafter. Prioritizing drug
offenses draws police resources away from reported crimes to unreported
ones. If this switch took place faster after Mapp in states that had not
had the exclusionary rule hitherto, all the data would show is the
effect of an exogenous change in law-enforcement taste.

The basic point, however, should not be lost. Any method of
enforcing legal limits on the police will cause some victimization of
innocent people--including some murders. Put another way, how should we
characterize the Atkins and Rubin numbers? Do they reflect the high
price of Warren Court activism? Or do they reflect the marginal benefits
of lawless policing, including midnight entries, pumping stomachs,
planting microphone in private bedrooms, and indefinite detention
incommunicado on suspicion--all, of course, without warrants?

(102.) See Jeffries, supra note 68, at 267.

(103.) See id. ("[I]n cases of flagrant misconduct (of the
sort that might trigger criminal prosecution), a government might cut
its employee loose, but it is hard to imagine a case of simple search
and seizure (unaccompanied by assault or other grievous harm) provoking
that reaction. Thus, although government officers cannot capture the
social benefits of their actions, neither do they pay the full
costs.").

(104.) The political incentives facing public officials responsible
for the police are distinctly tilted in favor of security over liberty.
I remain convinced of the basic soundness of the position I advanced in
Donald A. Dripps, Criminal Procedure, Footnote Four, and the Theory of
Public Choice, OR." Why Don't Legislatures Give a Damn About
the Rights of the Accused?, 44 SYRACUSE L. REV. 1079 (1993). For a more
recent resume of the supporting arguments, see Donald A. Dripps, Justice
Harlan on Criminal Procedure: Two Cheers for the Legal Process School,
30Hlo ST. J. CRIM. L. 125, 145-50 (2005). Professor Rosenthal, in
distinguishing public from private liability-based incentives, seems to
agree that sanctions that might be optimal from the perspective of a
private firm may be inadequate to ensure constitutional compliance by
public entities. See Lawrence Rosenthal, A Theory of Governmental
Damages Liability. Tort, Constitutional Torts, and Takings, 9 U. PA. J.
CONST. L. 797, 842-43 (2007) ("Even aside from political
opportunity costs, liability-producing conduct may have political
benefits that offset the deterrent effect of liability. To use Professor
Levinson's example, a program of aggressive stop-and-frisk of young
males in high-crime areas may increase liability, but it also may pay
such handsome political benefits that liability will have no deterrent
effect." (citation omitted)).

(105.) See Nix v. Williams, 467 U.S. 431 (1984).

(106.) See Dripps, supra note 17.

(107.) See, e.g., Richard H. McAdams, The Political Economy of
Entrapment, 96 J. CRIM. L. & CRIMINOLOGY 107, 146 (2005); see also
U.S. Dep't of Justice, Fed. Bureau of Investigation, 2008 Crime in
the United States, available at http://www.fbi.gov/ucr/cius2008/
offenses/clearances/index.html.

(108.) See Jeffries & Rutherglen, supra note 84, at 1407
("One suspects that many courts in many places strain to avoid
[exclusion in border-line rather than flagrant cases]. Yet it is
precisely in the context of the borderline mistake, the everyday close
call that should have been made differently, that alternative remedies
are hardest to find." (citations omitted)).

(109.) 456 U.S. 798, 804-25 (1982) (holding that where a police
officer had probable cause to believe that an automobile contained
narcotics, the officer could open a paper bag in the trunk of the car
without first obtaining a warrant).

(110.) 500 U.S. 565, 575-76 (1991) (holding that where a police
officer had probable cause to believe that a paper bag in the trunk of a
suspect's auto contained marijuana, the police officer could open
the paper bag without first obtaining a warrant).

(111.) This term comes from the case Terry v. Ohio, 392 U.S. 1
(1968), which held permissible a reasonable search for weapons for the
protection of the police officer where he has reason to believe that the
individual is armed and dangerous, regardless of whether he has probable
cause to arrest the individual for a crime. Id at 27.

(112.) See Maryland v. Pringle, 540 U.S. 366, 371 (2003) ("The
probable-cause standard is incapable of precise ... quantification into
percentages because it deals with probabilities and depends on the
totality of the circumstances....'[T]he substance of all the
definitions of probable cause is a reasonable ground for belief of
guilt.'" (citations omitted)). In the leading case, Illinois
v. Gates, 462 U.S. 213, 238 (1983), the Court equated probable cause
with a "fair probability." One might argue the reverse--that
"less likely than not" can be equated with
"improbable," and therefore no probability at all. On the
other hand, in Prindie the majority shied away from any numerical
expression of required probability. Probably the best that can be said
is that the probable cause standard is "a relatively high level of
certainty akin to a more-likely-than-not standard...." Christopher
Slobogin, Transaction Surveillance by the Government, 75 MISS. L.J. 139,
150 (2005).

(115.) RICHARD VAN DUIZEND ET AL., THE SEARCH WARRANT PROCESS:
PRECONCEPTIONS, PERCEPTIONS, AND PRACTICES 46-50 (1983). These
percentages were obtained by taking the percentage of searches in cases
in which returns were filed that led to seizure of some item named in
the warrant, and multiplying that percentage by the percentage of
warrants for which returns were in fact filed.

(118.) See Stuntz, supra note 92, at 848 ("[R]equiring a
warrant is a good thing if, but only if, the substantive standard
applied to the search would otherwise be too low--if, that is, police
will be too quick to search unless they are forced to get a
warrant.").

(122.) Id. at 679 ("[Troopers] very likely did distort the
records in these data by simply failing to report unsuccessful searches,
a type of conduct that is also familiar from reports in New Jersey and
New York." (citations omitted)).

(123.) Id. at 700 tbl.14. The 9.8% figure is obtained by adding the
3.7% hit rate for small dealers to the 6.1% hit rate for medium/large
dealers.

(124.) WILLIAM R. SMITH ET AL., THE NORTH CAROLINA HIGHWAY TRAFFIC
STUDY, FINAL REPORT TO THE NATIONAL INSTITUTE OF JUSTICE, U.S.
DEPARTMENT OF JUSTICE 157 (2003) ("The regular road troopers we
talked to were not enthusiastic about searches in the least, and it is
clear that they view unnecessary searches, in general, as a
nonproductive use of their time.").

(125.) 392 U.S. 1 (1968) (finding permissible a reasonable search
for weapons for the protection of the police officer where he has reason
to believe that the individual is armed and dangerous, regardless of
whether he has probable cause to arrest the individual for a crime).

(126.) United States v. Sokolow, 490 U.S. 1, 7 (1989) (quoting
Terry, 392 U.S. at 30).

(127.) Florida v. J.L., 529 U.S. 266, 271 (2000).

(128.) Illinois v. Wardlow, 528 U.S. 119, 124 (2000).

(129.) CIVIL RIGHTS BUREAU, OFFICE OF THE N.Y. ATTORNEY GEN., THE
NEW YORK CITY POLICE DEPARTMENT'S "STOP AND FRISK"
PRACTICE: A REPORT FROM THE OFFICE OF THE ATTORNEY GENERAL 160-62
(1999), available at http://www.oag.state.ny.us/bureaus/civil_
rights/pdfs/stp_ffsk.pdf.

(130.) See James J. Fyfe, Stops, Frisks, Searches, and the
Constitution, 3 CRIMINOLOGY PUB. POL'Y 379, 393 (2004)
("Whether and how many of these stops were, in fact,
unconstitutional, is a question that will never be resolved.").

(134.) See Fyfe, supra note 130, at 390 (suggesting a
"replication of Gould and Mastrofski's work in an agency in
which officers are more carefully trained and held
accountable...."). To their credit, Gould and Mastrofski addressed
this problem, both by coding according to certainty of
legality/illegality, and by opting to code as legal in indeterminate
cases. It is therefore possible that their estimate of 30% noncompliance
is low, rather than high. See Gould & Mastrofski, supra note 131.

(135.) See Fyfe, supra note 130, at 384 ("This [research]
group's assessment of what was constitutional and what was not was
only marginally better than that of the police who had been
observed.").

(136.) GREG RIDGEWAY, ANALYSIS OF RACIAL DISPARITIES IN THE NEW
YORK POLICE DEPARTMENT'S STOP, QUESTION, AND FRISK PRACTICES xi
(2007).

(137.) Id. at xv.

(138.) Id. at 37 tbl.5.2.

(139.) Id. at 41-42 & tbl.5.5.

(140.) Id. at 42 tbl.5.5.

(141.) Id.

(142.) Id. at xiv.

(143.) 529 U.S. 266 (2000).

(144.) City of Indianapolis v. Edmond, 531 U.S. 32, 35 (2000).

(145.) J.L., 529 U.S. at 269.

(146.) Id

(147.) Susan Saulny, Chicago Police Abuse Cases Exceed Average,
N.Y. TIMES, Nov. 15, 2007, at A24, available at
http://www.nytimes.com/2007/11/15/us/15chicago.html. Some complaints are
false; but many citizens decline to complain because they expect no
action or fear reprisal.

(148.) The Bureau of Justice Statistics reports that in 2004, the
most recent data available, there were 1,100,210 arrests for selected
serious felonies in the state systems, but only 466,480, or just over
42%, resulted in convictions. See Sourcebook of Criminal Justice
Statistics Online, tbl.5.0002.2004,
http://www.albany.edu/sourcebook/pdf/t500022004.pdf (last visited Apr.
26, 2010). The Table lists the offenses differently; I generated my
number by summing the arrests and convictions across all offenses
listed.

(151.) Kamisar, supra note 12, at 600 (describing Weeks as
approving the view that loss of evidence is attributable to the Fourth
Amendment rather than to the exclusionary rule).

(152.) Herring, 129 S. Ct. at 707 (Ginsburg, J., dissenting).

(153.) 401 U.S. 560(1971).

(154.) 277 U.S. 438 (1928).

(155.) Id. at 568-69.

(156.) Id.

(157.) Boyd v. United States, 116 U.S. 616 (1886).

(158.) See Olmstead v. United States, 277 U.S. 438, 478-79 (1928)
(Brandeis, J., dissenting) ("The makers of our Constitution
undertook to secure conditions favorable to the pursuit of happiness.
They recognized the significance of man's spiritual nature, of his
feelings and of his intellect. They knew that only a part of the pain,
pleasure and satisfactions of life are to be found in material things.
They sought to protect Americans in their beliefs, their thoughts, their
emotions and their sensations. They conferred, as against the
government, the right to be let alone--the most comprehensive of rights
and the right most valued by civilized men. To protect that right, every
unjustifiable intrusion by the government upon the privacy of the
individual, whatever the means employed, must be deemed a violation of
the Fourth Amendment. And the use, as evidence in a criminal proceeding,
of facts ascertained by such intrusion must be deemed a violation of the
Fifth.").

(159.) Entick had held that the common law knew no warrant to
search for mere evidence, and Boyd had held that a court order
compelling production of private papers, obtained after adversary
process, violated the Fourth and Fifth Amendments. Brandeis viewed
private conversations as on a par with private papers (if not yet more
sacrosanct), and thus beyond surveillance even under warrant. Note the
inclusion of papers compelled "in the orderly process of a
court's procedure," id. at 477-78, as within the rule of Boyd,
and the inflexible conclusion of the famous right-to-be-let-alone
passage that any use of the conversations in evidence violates the Fifth
Amendment. Justice Ginsburg notably did not cite Justice Black's
opinion in Mapp, the last defense of the exclusionary rule on
self-incrimination grounds to be found in the U.S. reports (and perhaps
the last, period). At that time, even those sympathetic to the
exclusionary rule recognized the weaknesses of the self-incrimination
theory. See Francis A. Allen, Federalism and the Fourth Amendment: A
Requiem for Wolf, 1961 SUP. CT. REV. 1, 25-26 (noting historical,
analytical, and practical weaknesses of the self-incrimination theory,
and expressing skepticism about the continuing relevance of Justice
Black's "individualism" on the issue).

(165.) See, e.g., Myron W. Orfield, Jr., Deterrence, Perjury, and
the Heater Factor: An Exclusionary Rule in the Chicago Criminal Courts,
63 U. COLO. L. REV. 75, 80-81 (1992) (using a study conducted on Chicago
policemen to illustrate higher instances of perjury in instances of
Fourth Amendment violations). Orfield also found that "[m]any
respondents commented that to the extent a tort remedy would actually
impose damages on police officers, it would cause the police to perjure
themselves even more frequently." Id. at 126.

(166.) See TOWARDS A NORMATIVE THEORY OF THE CRIMINAL TRIAL 236-52
(Antony Duff et al. eds., 2007) (arguing that the integration principle,
i.e., unitary transaction theory, and "moral standing of the
trial" may call for excluding improperly obtained evidence);
Kamisat, supra note 12, at 590-97 (advancing the principle of judicial
review as a justification for exclusion); Thomas S. Schrock & Robert
C. Welsh, Up From Calandra: The Exclusionary Rule as a Constitutional
Requirement, 59 MINN. L. REV. 251, 257-60 (1974) (characterizing search
and use of evidence at trial as a "unitary transaction," and
defending the exclusionary rule as a necessary form of judicial review
under Marbury v. Madison).

(167.) This is the example alluded to in TOWARDS A NORMATIVE THEORY
OF THE CRIMINAL TRIAL, supra note 166, at 228, as a reason for rejecting
deterrent theories of exclusion. As the authors state there, "when
considering whether wrongfully obtained evidence should be excluded, the
relevant comparator terms of deterrent effect is not failing to respond
to the wrong, but rather using alternative sanctions for the
wrong." Id. No explanation is later given why this is not also the
"relevant comparator" for assessing judicial complicity in the
prior illegality or the "moral standing of the trial."

One problem with deontological approaches is that they invite
recharacterization of countervailing considerations as rights-claims.
Professor Pettys's contribution to this Symposium takes such a
tack. See Todd Pettys, Instrumentalizing Jurors: An Argument Against the
Fourth Amendment Exclusionary Rule, 37 FORDHAM URB. L.J. 837 (2010). I
have grave doubt about whether this exceptionally creative turn is
convincing, as it calls into question not just all exclusionary rules
unjustified by reliability considerations (such as the rules against
proof of subsequent remedial measures in civil cases, or proof of
statements made during plea negotiations in criminal cases), but also
seems to call into question settlements qua settlements, at least those
entered into after the jurors are sworn. I may have misunderstood
Professor Pettys's claim, but his article illustrates that those
who recognize deontological entitlements to exclusionary rules of
evidence must also fend off claims of conflicting rights to truth in
adjudication. See id.

(168.) See, e.g., Commonwealth v. Dana, 43 Mass. 329, 337 (1841)
("There is another conclusive answer to all these objections.
Admitting that the lottery tickets and materials were illegally seized,
still this is no legal objection to the admission of them in evidence.
If the search warrant were illegal, or if the officer serving the
warrant exceeded his authority, the party on whose complaint the warrant
issued, or the officer, would be responsible for the wrong done; but
this is no good reason for excluding the papers seized as evidence, if
they were pertinent to the issue, as they unquestionably were.").

(169.) Id. ("When papers are offered in evidence, the court
can take no notice how they were obtained, whether lawfully or
unlawfully; nor would they form a collateral issue to determine that
question.").

(170.) See Posner, Excessive Sanctions, supra note 93, at 640-41
("[T]he tort approach has its own problem of overdeterrence.... We
can fix this problem by immunizing police officers from tort liability,
thereby externalizing some costs in order to eliminate a disincentive
for the police to produce external benefits. But can we do this without
also underdeterring police misconduct? We can--by ensuring that an
officer's immunity for misconduct (committed in good faith) is not
extended to the agency employing him."). Judge Posner's
proposal, however, has not been adopted. In practice, the police
employer agrees to defend-and-indemnify the individual officers, who do
have qualified immunity to prevent overdeterrence. There is, however, no
general rule of entity liability. Monell v. Dep't of Soc. Servs. of
N.Y., 436 U.S. 658, 690-91 (1978). If the individual officers are not
personally liable, they owe no damages, and so the employer's
indemnification agreement requires no payment for damages.

(171.) If we are living in the '80s, as this "new"
debate suggests, I might as well repeat something I said then, and is no
less true now:

The evil of the search lies not in the discovery of criminal
evidence, but in the concomitant exposure to the government, and
thereby the world, of all those telltales of personality revealed
in any place we take for private. To view the exclusionary rule as
a personal right is to constitutionally enshrine the pistol in the
basement or the cocaine in the coffee can, and to ignore as
immaterial the music on the stereo, the books on the shelf, and the
fading letters in the bedroom bureau drawer.

(173.) See Amsterdam, supra note 34, at 437 ("[U]pon a proper
regulatory view of the fourth amendment and its implementing
exclusionary rule, there is no necessary relationship between the
violation of an individual's fourth amendment rights and exclusion
of evidence.").

(174.) Albert W. Alschuler, The Exclusionary Rule and Causation:
Hudson v. Michigan and its Ancestors, 93 IOWA L. REV. 1741, 1764 (2008)
("For more than forty years, the Court has denigrated
'rights' theories of the rule and contended that exclusion
never vindicates the interests of the defendant before the court. The
Court has insisted that exclusion is always what the Hudson Court said
it never can be--a windfall awarded to a defendant for the sake of
protecting the rights of others.").

(175.) See Amsterdam, supra note 34, at 437 (suggesting "a
rule excluding from evidence everything that an officer finds in the
course of a 'frisk' except weapons" in order to
discourage frisks initiated for the subjective purpose of finding
narcotics as opposed to weapons).

(176.) See People v. Martin, 290 P.2d 855, 857 (Cal. 1955)
("[I]f law enforcement officers are allowed to evade the
exclusionary rule by obtaining evidence in violation of the rights of
third parties, its deterrent effect is to that extent nullified.").
Justice Traynor's view was rejected by the U.S. Supreme Court, and
later, by the California voters. The Supreme Court, however, has adopted
a theory of the exclusionary rule that comports with Justice
Traynor's argument for target standing, and has never
satisfactorily answered his reasoning.

(184.) See, e.g., Jerold H. Israel, Criminal Procedure, the Burger
Court, and the Legacy of the Warren Court, 75 MICH. L. REV. 1319, 1412
(1977) ("[K]ey to the rule's effectiveness as a deterrent lies
... in the impetus it has provided to police training programs that make
officers aware of the limits imposed by the [Constitution] and emphasize
the need to operate within those limits." (citation omitted)).
Professor Slobogin is skeptical about the success of police training
programs. See Slobogin, supra note 84, at 393. The record of police
responses to Mapp, and to various specific changes in Fourth Amendment
law, see Dripps, supra note 17, at 14, suggests exclusion influences
police behavior, and it is hard to see how training could play no part
in improved compliance. On the other hand, if the studies Slobogin cites
turn out to be correct, so that sanctions rather than training are the
only way to improve compliance, virtual deterrence can adjust to this
reality by conditioning admissibility on discipline rather than
education. So long as there is some administrative response that does
discourage future violations, virtual deterrence can incorporate that
policy response.

(185.) See Orfield, supra note 165, at 80 (Chicago narcotics
officers reported that both superiors and peers were involved in
individual officers' suppression rulings; frequent loss of evidence
in suppression hearings could result in reassignment and bad faith
violations might lead to dismissal in extreme cases).

(186.) See supra Part II.C.

(187.) FED. R. EVID. 407.

(188.) See, e.g., Flaminio v. Honda Motor Co., 733 F.2d 463, 469-70
(7th Cir. 1984) (holding that the rule's anti-deterrent policy
applies in strict-liability actions as well as negligence actions). The
majority of the circuits took this position, and it was subsequently
written into the text of the Rule in 1997.

(189.) See FED. R. EVID. 407 advisory committee's notes
("The amendment to Rule 407 makes two changes in the rule. First,
the words 'an injury or harm allegedly caused by' were added
to clarify that the rule applies only to changes made after the
occurrence that produced the damages giving rise to the action. Evidence
of measures taken by the defendant prior to the 'event'
causing 'injury or harm' do not fall within the exclusionary
scope of Rule 407 even if they occurred after the manufacture or design
of the product.").

(190.) See supra Part II.A.

(191.) Often there is a collective bargaining agreement
("CBA") between the employer and the officers, with a
provision for arbitration. See, e.g., Whittie v. Doyle, 228 F.
App'x 512 (6th Cir. 2007) (arbitration hearing resulted in findings
adverse to plaintiff, who then sued on free-speech-retaliation grounds).
With or without a CBA, due process guarantees tenured employees a
hearing before termination. See, e.g., Urban v. Tularosa, No. 97-2292,
1998 WL 694465, at *4 (10th Cir. Oct. 6, 1998) (police officers
"with a property interest in continued employment" are
entitled to pre-termination notice and the opportunity to defend). Due
process does not appear to require a hearing before reprimands of record
that do not adversely change the employee's stature or
compensation. See Bloodworth v. City of Phoenix, 26 F. App'x 679,
682 (9th Cir. 2002).

(192.) See John Kaplan, The Limits of the Exclusionary Rule, 26
STAN. L. REV. 1027, 1046 (1974) (urging exception for "treason,
espionage, murder, armed robbery and kidnapping by organized
groups"). For a review and critique of similar proposals, see Yale
Kamisar, "Comparative Reprehensibility" and the Fourth
Amendment Exclusionary Rule, 86 MICH. L. REV. 1 (1987). For the
suggestion that seriousness-of-offense factors into substantive Fourth
Amendment doctrine, see Stuntz, supra note 92, at 866.

(193.) 468 U.S. 981 (1984) (admitting evidence of homicide found
during search authorized by hastily-modified form narcotics warrant that
was not altered to particularly describe the evidence of the homicide
described in the officer's affidavit).

(195.) 447 u.s. 727 (1980) (holding admissible against defendant
papers stolen from X, defendant's accountant, by surreptitious
warrantless entry of X's hotel room). The actual facts are even
more unsavory than the pallid parenthetical suggests.

(196.) See Dripps, supra note 113, at 929.

(197.) See LaFave, supra note 79, at 12 ("Perhaps the unstated
assumption is that deterrence by way of the exclusionary rule is not
needed with respect to negligent violations of the Fourth Amendment (or
some species of them) because a sufficient level of deterrence is
provided by some other force."). As LaFave points out, the only
candidate for some such countervailing incentive is police
professionalism, but that impulse is general rather than specific to
police record-keeping, and is in any event in substantial measure a
product of the exclusionary rule. See WALKER, supra note 63.

(198.) Nix v. Williams, 467 U.S. 431, 445 (1984).

(199.) Id. at 457 (Stevens, J., concurring).

(200.) See id. at 459 (Brennan, J., dissenting) ("To ensure
that this hypothetical finding is narrowly confined to circumstances
that are functionally equivalent to an independent source, and to
protect fully the fundamental rights served by the exclusionary rule, I
would require clear and convincing evidence....").

Donald A. Dripps, This Article benefitted greatly from comments
received at the University of Chicago Crime and Punishment Workshop.
Special thanks to Yale Kamisar for comments on an earlier draft.

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